Instruction Manual for Single Stage 350, 500, and 700 Frame Steam Turbines

9. Dresser-Rand part number, if known (optional).

M.6

Service

Dresser-Rand Turbine maintains repair facilities on a worldwide basis to repair

equipment needs with OEM manufactured parts. When contacting Dresser-Rand,

please have your turbine serial number available.

Contact a service center nearest you by using the link below:

http://www.dresser-rand.com/contactUs.php

A Service Representative can also be dispatched to your site to assist you in start-

ups, general maintenance, and troubleshooting by using the same link (above).

Have your turbine serial number available along with a date for when services will

be required.

The Technical Support group at the factory can address your technical questions by

using the contact information below:

Dresser-Rand Wellsville Operations

37 Coats St.

Wellsville, NY 14895

USA Tel: (Int’l +1) 585-596-3100

Fax (Int’l +1) 585-593-5815

When contacting the representative or factory, please specify the turbine serial

number, frame size, nature of the problem or service requirement, and date that

service is required.

M.7

Revamps (Rerates)

It’s not uncommon for the requirements of the steam turbine to change due to a

process change, more product output, or just a need to reduce energy consumption.

Steam turbine can have a broad operating range. Powers and speeds can be

modified with simple internal hardware changes while still maintaining the same

steam turbine case and footprint.

If you would like to have Dresser-Rand review your equipment, please use the

contact information above the find the nearest service center or contact the factory

direct. Have your serial number available along with the new conditions you

would like to operate at.

244

WARNING

Materials used in turbine construction (cast iron, steel, stainless

steel, special alloys) vary with steam conditions, speed, and

power. These materials were selected according to the original

rating of the turbine. NEVER attempt to re-rate a turbine without

the assistance of a Dresser-Rand manufacturer’s

representative and/or the factory. Misapplication of materials

could result in serious equipment damage and/or personal

injury.

M.8

Upgrades

Many of older turbines can be modified or upgraded to improve performance and

reliability. Improved designs in seals, bearings, controls, and blading can all be

incorporated into the existing machine when required.

If you would like to have Dresser-Rand review your equipment, please use the

contact information above and find the nearest service center or contact the factory

direct. Have your serial number available.

M.9

Factory Start-Ups

Authorized Dresser-Rand service representatives are available for start-up service

and to train operating personnel in the operation and maintenance of Dresser-Rand

steam turbines. An experienced service representatives will review your installation

prior to start-up, following established Dresser-Rand procedures.

Piping,

alignment, lubrication, overspeed trip, etc. will be carefully checked. Upon

commissioning the new installation, operating personnel will be trained.

Consult your Dresser-Rand manufacturer’s representative to schedule a start-up.

M.10

Parts Catalog

Refer to the applicable turbine cross sectional drawings included in the instruction

manual for a listing and location of the replacement part reference numbers used on

your turbine.

245

Section N Miscellaneous

N.1

Low Ambient Temperature Applications of Single

Stage ASTM A216-WCB Carbon Steel Pressure

Casing Steam Turbines

Dresser-Rand has been asked to provide a quotation for steam turbines that may be

installed into an area with an ambient temperature of -30°C (-20°C) or less.

The quoted D-R single stage turbine is offered with ASTM A216 Grade WCB

carbon steel pressure casing material that will meet the Charpy V-Notch Energy

requirements of ASME Pressure Vessel Code Section VIII, Division 1, UG-84 as

required by API 611 for ambient temperatures -30°C (-20°F) or higher. The

pressure vessel bolting is ASTM A193 Grade B7, and nuts are ASTM A194 Grade

2H or ASTM A563 Grade A, which also meet the requirements of the Pressure

Vessel Code and API 611for ambient temperatures of -30°C (-20°F) or higher. If

the offered turbine is installed into an area with ambient temperatures of lower than

-30°C (-20°F), the equipment user must take precautions to insure that the turbine

casing be kept warm and/or be warmed prior to equipment start-up to meet the

requirements of ASME Section VIII, Division 1, UG84, as appropriate.

When a steam turbine is in operation, the casing temperature s above the

brittle/ductile transition temperature of the casing material. Therefore, a low

ambient temperature is not a concern. However, to insure that the low ambient

temperature does not result in damage or failure of the turbine and its accessories, it

must be installed, started, operated, and shut down as described in the Low

Ambient Steam Turbine Application Guidelines outlined below. If compliance

with these guidelines and acceptance of the offered standard materials is not

possible, consult Dresser-Rand for further discussion or an alternate material

offering.

Prior to the purchase of the turbine, the final equipment user, driven equipment

vendor, and Dresser-Rand shall agree to the special precautions necessary with

regard to low ambient conditions that can occur during operation, maintenance,

transportation, erection, commissioning, and testing.

Dresser-Rand shall assume no liability of any nature for the offered turbine if not

transported, erected, installed, started, operated, maintained, and shut down as

described in compliance with the

“Low Ambient Steam Turbine Application

Guidelines” outlined in this document.

246

Low Ambient Steam Turbine Application Guidelines

Note these requirements apply to both API and non-API applications.

General:

When a steam turbine is to be installed where the ambient temperature could be -

30°C (-20°F) or lower, the following issues require special attention to insure that

the low temperature does not result in damage or failure of the turbine and/or its

accessories.

See the turbine instruction manual for additional turbine installation and

operational details and the accessory instruction manuals for their cold start/low

ambient precautions and recommendations.

Transportation:

The turbine is suitable for transporting to site, unloading, and placing in storage, or

transporting to site, unloading, and placing on its foundations, or moving from on-

site unheated storage to its foundations, only when ambient temperature is at or

above -30°C (-20°F).

Installation:

The turbine and its auxiliaries can remain out of service with no external source of

heat when the ambient temperature is at or above -45°C (-49°F), provided the

turbine is not disturbed when its metal temperature is below

-30°C (-20°F),

Turbine maintenance cannot occur unless the temperature of the turbine and all its

mechanical components is at or above -30°C(-20°F).

Turbine installation cannot proceed until the turbine and all its mechanical

components are t or above -30°C (-20°F). Alternatively, if the turbine components

are below -30°C (-20°F), the area musts be hooded and heated to raise the

component temperature above -30°C (-20°F).

Care must be taken to insure that the steam inlet and exhaust piping is properly

supported or equipped with flexible connections so they will not put excessive

force on the turbine when it is shut down. The turbine casing and inlet and exhaust

flange material are more prone to cracking when the ambient temperature is cold ad

their temperature is below the brittle/ductile transition temperature. This is of

increased concern if the piping is hot when the turbine is shut down and the inlet

and exhaust shut off valves are closed.

247

All turbine condensate drain connections and steam piping low points must be

properly drained to insure all condensate can be removed from the turbine and

steam system during shot-down. Similarly, cooling water lines to bearing housings

and water coolers, bearing housing water jackets, and oil coolers must be equipped

with drains to insure that water can be removed during shut-down.

Failure to remove all water from the turbine casing, piping, cooler,, bearing

housing, etc. when temperatures are below freezing could result in failure of the

piping and various other components.

If oil reservoirs, oil or water piping, bearing housings, and other components are

heat-traced, all local safety regulations and electrical codes must be adhered to.

Lubrication:

Dresser-Rand offers a variety of lubrication systems including oil ring lubrication,

oil ring lubrication with circulating oil cooling, circulating oil lubrication, mist oil

lubrication, and force feed lubrication.

When the ambient temperature is 15°C (60°F) or lower, it must be ensured that the

lubricating oil will circulate and that cooling water, if required, does not freeze

during operation or shut-down. Heat tracing or insulation of oil lines, bearing

housing, oil tanks, and water cooling lines may be required. Lubricant type and

required oil viscosities for turbine equipment packages are defined in the certified

drawings and data package and the applicable operation and maintenance manuals.

Viscosities for turbine lubrication are application specific, and the required

viscosity may range from ISO 32 (32cSt@40°C (100°F) 150 SUS @40°C (100°F)

up to ISO 100 (100 sSt @ 40°C (100°F) 550 SUS@40°C (100°F),

Use of the correct lubricants at the correct temperatures and viscosities is critical to

the trouble free operation of the turbine and its accessory equipment.

Accessories:

Some turbine accessories may require installation, heat tracing, special lubrication,

or adjustments for use in low ambient conditions. Others may require installation

into heated locations or preheating before use. The accessory instruction manuals

or accessory vendor must be consulted for additional guidance and precautions.

A partial list of typical turbine accessories might include governors, gauges, oil

pumps, control panels, instruments, reduction gears, lube oil systems, couplings,

steam piping, valves, solenoid valves, tachometers, ejectors, condensers, etc.

Turbine Start-Up:

248

Warming the Turbine Pressure Casing:

If metal temperature is at or below -30°C (-20°F), a warm-up of the complete

turbine must be performed prior to start-up, including the use of hooding and space

heating to elevate the metal temperature of all steam-contacted components to a

temperature of at least -30°C (-20°F) prior to the introduction of steam to the

turbine.

If metal temperature is above -30°C (-20°F), steam from the client’s exhaust steam

header piping may be used to preheat the cold back pressure turbine prior to start-

up. If exhaust steam is not available for this purpose, a small steam bypass line,

equipped with a valve, may be installed around the inlet block valve or start-stop

valve to allow preheating of the turbine casing with a small flow of inlet steam.

Allow the turbine casing to reach 15°C (60°F) or exhaust steam temperature before

proceeding further.

During warming, all turbine casing and associated steam piping drain valves must

be opened to allow liquid to drain from the turbine casing and its associated steam

piping. Take special care to insure all liquids are drained prior to closing the

valves for turbine start-up.

Prepare the Lubrication System for Start-Up

If the ambient temperature is less than 15°C (60°F), lubricating oil and, if supplied,

the lubrication system and oil piping must be warmed to 15,C (60°F) to insure that

the oil will flow to the bearings and back to the oil reservoir or oil tank.

For ring-oiled turbines, the oil temperature should be such that the oil rings will

turn and pick up the oil. This may require that a hot liquid be circulated through

the bearing housing “cooling” water jackets.

“Cooling water,” if less than 15°C

(60°F), which may be required during normal turbine operation, should not be

applied to the bearing housing water jackets until the bearing housing temperature

exceeds 15°C (60°F), which may be required during normal turbine operation. For

turbines equipped with pressure lubricating or circulating oil systems, the lubricant

must be warmed to a viscosity such that the oil pump will prime and deliver

lubricant to the turbine bearings. His may be accomplished by use of a steam

heating coil or electric heating element. If electric heating elements are used, the

watt density should not exceed 23W/in² (3.5W/cm²), and a sheath temperature of

100°C (212°F) to avoid carbonizing the oil. After the lubricant is warmed, it must

be circulated throughout the entire lubrication system by means of a hand, motor,

or steam driven pump to warm all the associated lubrication system components

prior to turbine start-up.

249

After heating the lubricating oil or determining that it does not require heating, start

the turbine per the instruction manual. Turn the turbine over slowly for a short

time, insuring that the oil rings are turning and/or the lubrication system is

delivering lubricant to the turbine bearings.

Operation:

Operate in accordance with normal operating routine, except that to maintain

suitable lubricating oil temperature and viscosity, it may be necessary to heat the

oil instead of cool the oil, especially if there are long un-insulated or unheated oil

lines between the turbine and a remote lubrication system.

With some turbine speed governors, a change in the governor oil viscosity may

have an effect on the speed of the turbine. Therefore, when operating a turbine in

low ambient temperature, it may be necessary to make manual adjustments on the

speed governor.

Shut Down

After the unit is shut down in accordance with the instruction manual, special care

must be taken to insure that all water is drained from the steam lines, turbine

casing, bearing housing water jackets, valves, oil coolers, etc. Freezing water in

the turbine or its associated systems can cause major damage or problems during

the next turbine start-up. Any lubricant or accessory heating system should be

turned off to avoid overheating unless advised otherwise by the manufacturer’s

instruction manual.

If there is steam from other processes in the exhaust piping, leave the exhaust valve

open. If the turbine is to be shut down or a short period of time or is on standby,

thereby avoiding the need to preheat the pressure casing on restart. Case drain

valves should be left open.

When properly drained of water, the turbine and its auxiliaries can remain out of

service with no external source of heat when the ambient temperature is at or above

-45°C (-49°F) as long as the turbine is not disturbed when its metal temperature is

below -30°C (-20°F). Turbine maintenance cannot occur unless the turbine and all

is mechanical components are at or above -30°C (-20°F).

250

N.2 “Quick” Start,”Fast” Start, “Automatic” Start

Dresser-Rand Single Stage Steam Turbines

In the case of a “quick” start when the turbine is not thoroughly warmed nor

gradually brought up to the minimum governor speed, the principal areas of

concern are: (1) water slugging (2) bearing lubrication, (3) rotor acceleration rate,

and especially (4) sudden temperature differentials across the turbine.

1 Water Slugging

Since the velocity of a water particle passing through a turbine is low relative to the

steam and rotating blade velocity, such particles can cause extensive damage as

they impinge on the rotating blading. Furthermore, the downstream force

generated by such particles impinging on the rotor blading can be high enough to

cause thrust bearing failure. The warming of a steam turbine allows for

vaporization and removal of condensate in the steam inlet line ahead of the turbine

and in low points of the casing.

2 Lubrication

Without immediate and constant oil feed, the heat generated by the shaft in the

turbine bearings, unless properly dissipated, can cause bearing failure. Oil ring

lubricated bearings provide immediate lubrication as the shaft begins to turn, so

long as the proper oil level is maintained in the bearing housings. With pressure

lubricated bearings, the lubrication system must be arranged such that oil fills the

supply lines and feeds the bearings when the shaft begins to turn.

3 Acceleration Rate

With steam turbine applications that are started with no load, the acceleration rate

of a low inertia rotating element can be so high that the control system response to

close the steam admission valve does not react prior to overspeed trip. This

particularly true of the turbine generator sets which may also require limited

frequency variations in the electrical system. In instances such as this, a ramp

effect on governor valve closure may be built in the control system.

4 Temperature Differential

On turbines with built-up rotors, the disc-to-shaft allowance tends to decrease to

unacceptable limits with a 200°F (93°C) temperature differential between the disc

and shaft. The probability of such a condition existing is greater at approximately

five minutes after start-up, rather than immediately at start-up. Loss of shrink fit

can result in axial; or wobble movement of the disc on the shaft, possibly resulting

in turbine breakdown. The colder the unit at start-up, the greater the probability of

the temperature differential occurring. Since the utilization of forged discs in lieu

251

of plate discs allows a higher shrink fit, we normally recommend the customer

consider using forged discs.

5 General:

The subject of “quick,” “fast,” or “automatic” start is not something new in the

steam turbine industry. Nor has Dresser-Rand decreased its engineering standards

for design of steam turbine shafts, bearings, or shrink fit of discs to shafts.

In general, reliability and durability are compromised by quick starting of a turbine

and will result in shortened overall turbine life. Frequent quick starts are

particularly severe on bearings and rotating elements. The more rapid the

acceleration rate, the higher are the transient loadings and the more severe are the

loading effects.

Dresser-Rand single stage turbines with standard construction are suitable for start-

up in five seconds provided the following conditions are met:

1. The inlet side of the turbine steam line must be trapped.

2. Proper lubrication of bearings must be provided.

3. The inlet temperature of the steam shall not exceed

750°F (399°C).

4. The differential temperature between inlet steam and

exhaust steam shall not exceed 350°F (177°C).

5. Back pressure shall be maintained on the casing during

shut-down.

(This in itself is not a recommended

operating condition due to possible shaft wire cutting or

carbon ring seal decay, but will keep the casing warm).

6. The operating speed of the turbine shall not exceed 6000

RPM.

7. The unit must be brought up under load.

In operating a turbine under the above conditions, the user must bear the

responsibility for bearing failure, loss of disc-to-shaft fit, and carbon ring decay.

252

N.3 Dresser-Rand Standard Policy on Equipment Sound

Levels

It is Dresser-Rand’s intention to design and manufacture turbines with satisfactory

sound levels and work cooperatively with the user to make the overall installation

as quiet as possible. However, there are many environmental factors affecting

sound measurements which are beyond Dresser-Rand’s control. These might

include piping, room size, and other equipment or structures near the unit which

may tend to focus, reflect, or amplify sounds, as well as emit other sounds. In view

of this, Dresser-Rand is unable to guarantee noise levels other than to commit to a

willingness to assist the end user in corrective action (at end user’s cost) in cases

where a noise problem may be perceived to be present.

Expected sound levels for various types of Dresser-Rand-built equipment operating

at full load in a typical field installation are given below. Sound levels for the

turbine or gear alone isolated in a non-reflecting environment may be significantly

lower.

Octave Band Center

Expected Sound Pressure Levels

Frequency (HZ.)

(dB-Ref. 2 x 10⁵ Nm²

Single Stage

Multistage

Reduction

Turbines

gears

Acoustic Insulation 

Yes

105

104

103

102

125

250

500

1000

2000

4000

8000

Expected Over-All

(dBA)

The breakdown above gives maximum expected dB levels for each octave band

under typical operating conditions. Actual values for each octave band would

normally not equal all these maximum values. Hence, expected over-all sound

levels given above for each type of equipment are lower than the sum of the

individual (maximum) values.

253

Section O

O.1 LIST OF POSSIBLE INSTALLED ELECTRICAL

PARTS AND THEIR APPLICATIONS ON 350/500/700

SST TURBINES

There are numerous combinations of electrical devices installed in some

turbines. Below is a listing of the possible electrical components found on SST

turbines in various configurations.

Electronic Governor. Some of the electronic governors used on the SST

turbines are manufactured by Tri-Sen, Compressor Controls Corporation, and

Woodward. Magnetic speed sensors, in most cases a quantity of two, are

installed either external to the exhaust end bearing case or internally or

externally on the steam end bearing case. The sensors read a gear internally

mounted on the rotor shaft and are wired typically by the customer to the

electronic governor input location. The electronic governor serves the same

purpose as a mechanical governor

(covered elsewhere in this manual) for

controlling turbine speed. The electronic governors provide an analog signal

output which can be utilized for remote customer DCS monitoring purposes.

Electronic governors also provide a means for relay control which can be

programmed to alarm and or trip other customer processes, as well as an option

for remote control via a switch panel either provided by the customer or

installed by Dresser-Rand. The electronic governors maintain turbine speed

through the use of an actuator. The actuator adjusts the governor valve in

response to the typical 4-20 mA signal received from the electronic governor.

A governor program is part of the documentation provided the customer

when an electronic governor is applied. Within the governor program are

the parameters, which are entered via keypad into the governor, when it is

programmed for operation.

Magnetic Speed Sensors. The electronic governors, tachometers, and

electronic over-speed protection require the use of speed probes to provide a

voltage-pulsed input for accurate turbine control. Each sensor is factory set to

the recommended adjustment gap between the probe tip and target.

254

Limit Switch. The trip and throttle valve may have a limit switch mounted on

the valve to indicate closed position of the valve. The contacts can be

configured as normally open or normally closed per customer requirement.

Solenoid operated emergency trip valve. The over-speed tripping of the

turbine can be accomplished by a mechanical method covered elsewhere in

this manual. Electronic options are available to trip the turbine in an over-

speed condition through a solenoid valve which dumps the air or control oil

from the trip valve operational configuration. D-R recommends that the

solenoid valve be wired through an interposing relay to safely sustain the

current required for the solenoid valve operation.

A customer controls interface is required if it is desired to have a customer trip

signal incorporated into the emergency tripping of the turbine. This set of controls

needs to be accomplished via a trip string of series interconnected contacts, any of

which would de-energize the trip solenoid valve, thereby tripping the unit.

Vibration Monitoring. The turbine shaft radial movements at both the steam

end, exhaust end, and axial thrust bearing displacement can be accomplished

by vibration probe and proximitor hardware. In addition to the radial and

axial probes is the inclusion of a keyphasor probe for the Bently Nevada

asset monitoring equipment, which is D-R’s standard vibration monitoring

recommended vendor. The vibration probes are sized and installed in the

bearing cases for optimum length to clear accessories mounted on or near the

bearing case. Proximitors are typically shipped installed into a junction box

or loose. In some cases provisions only are provided the customer and

installation holes in the bearing cases are plugged.

Bearing Temperature Monitoring. D-R offers RTD or thermocouple

electronic bearing temperature monitoring capabilities. The bearings can be

equipped with the customer-specified instruments embedded within the

bearings by D-R. The temperature instrument wires exit through the bearing

case through Minco trade name seals where terminal heads are then

installed, providing wire termination points. Single and dual element

temperature instrumentation is available.

When provisions for future

temperature monitoring are requested by the customer, bearing cases have

installation holes machined and plugged so that bayonet style RTDs or

thermocouples could be installed at a later time.

Seismic Bearing Case Monitoring.

Accelerometers are available for

installation on the bearing cases, an alternative to the more sophisticated

probe and proximitor type of shaft monitoring. They monitor the rotational

vibration levels being transmitted to the bearing case.

Electronic Speed Monitoring (tachometer). Electronic tachometers are available for

local and remote speed monitoring. Some tachometers have programmable relays for

optional alarm and trip interface with customer DCS or PLC equipment. Self-powered

255

tachometers are an available option. In most cases only one magnetic speed sensor is

required for use with the tachometer.

Electronic Overspeed Protection.

Over-speed tripping of the turbine can be

accomplished by a mechanical method covered elsewhere in this manual. Electronic

options are available to trip the turbine in an overspeed condition through a solenoid

valve which dumps the air or control oil from the trip valve operational configuration.

D-R recommends that the solenoid valve be wired through an interposing relay to safely

sustain the current required for the solenoid valve operation. There are three magnetic

pickup speed probes supplying signals to the over-speed protection device.

Over-speed trip devices are composed of three separate modules which are in communication

with each other. If one magnetic pickup fails, the unit will continue to operate with the two

remaining speed input signals but will trip when one of the signals exceeds the over-speed trip

setting on one of the modules. Normal operation compares the three speed signals and takes

the two highest out of the three signals to trip the turbine, hence the name two out of three.

During the programming of the over-speed device it is of utmost importance that the exact

number of targets being read by the speed probes be correctly entered.

Electronic/pneumatic throttle valve actuator and controls. Any SST turbine with an

electronic governor requires an actuator to be attached to the inlet governor valve to receive the

signals from the governor for valve movement and positioning and, if desired, provide valve

position feedback for monitoring. The most common actuator used, the electro-pneumatic

actuator, has a current to pressure interface where the electronic governor, via analog signal, is

electrically connected to the actuator and accurately controls its force/movement on the throttle

valve.

Electronic pressure transmitters. There are some instances where a remote pressure

measurement is required, which can be provided with an electronic pressure transmitter. There

are several types of communication methods available by which the transmitter can interface

with the customer PLC or DCS.

Electronic temperature transmitters. There are some instances where a remote temperature

measurement is required, which can be provided with an electronic temperature transmitter.

There are several types of communication methods available by which the transmitter can

interface with the customer PLC or DCS.

O.2

Electrical Component Removal and Replacement

CAUTION

256

DO NOT perform work on any live electrical device or

component without a thorough lockout/tagout procedure in

place.

WARNING

Only professionally certified electricans are to be working on

the SST electrical components.

The upper half of the turbine exhaust and steam end bearing cases must be removed

to gain access to the shaft bearings and turbine rotor for RTD and thermocouple

access. See section L.3 for turbine case disassembly.

The procedure for removing and replacing the radial and journal bearings, which contain the

temperature monitoring hardware, is presented in section L.6.

Magnetic pickups are mounted on either the steam end or exhaust end bearing cases and can be

removed and replaced per field instruction procedures without the removal of the bearing cases.

Terminal heads can be removed from the pickup via the union and wiring removed from the

terminal blocks. In some instances the magnetic speed probes are installed inside the bearing

cases, in which case the bearing case must be disassembled to facilitate probe removal.

Limit switches indicating T&T valve position can be accessed from the outside of the valve and

removed by removal of the flexible conduit attached to the switch and removal of wiring from

the terminal blocks.

Vibration probes are mounted into the external cover of the bearing cases and can be removed

and replaced without turbine disassembly. Adjustment of the probes is accomplished with a

voltmeter set on DC voltage and turned until the voltage reads 9 volts DC whereby the locking

nut is secured in place.

The electro-pneumatic actuator is readily removable from the throttle valve body and removal

of flexible conduit and wiring disconnection from the terminal blocks.

The governor and over-speed protection equipment are shipped loose to be installed in the

customer control room, in most cases. For those cases where they are not shipped loose, both

devices are installed in a skid-edge enclosure with operators mounted on the external enclosure

door allowing for local governor operation when installed in a hazardous location. Wiring can

be removed from the terminal blocks allowing the components to be replaced.

In some cases, where there are RTDs and vibration probes as well as limit switch indicators of

the T&T valve position, there could be enclosures containing terminal blocks. These enclosures

257

could be installed on the turbine base on a junction box stand with conduit running from each

electrical device, mounted on the steam turbine, to the enclosure.

Accelerometers are installed externally on the bearing case caps and are readily accessible for

removal and probe cable disassembly and re-assembly.

Tachometers are shipped loose in most cases. They can be easily removed and replaced by

removal of the flex conduit at the union and disconnection of wiring from the terminal blocks.

Pressure and temperature transmitters are typically locally mounted by D-R and wired by the

customer. In cases where there is a skid-mounted enclosure, disconnection and reconnection

from terminal blocks and flex conduit with a union can remove the transmitter wiring.

O.3

Electrical Certification and Standards

The electrical components installed on all SST turbines are selected to satisfy the

specific electrical area classifications indicated/required by the customer. All

wiring is performed to meet current codes of the various countries where the SST

turbines will be operating: NEC

(National Electric Code), IEC

(International

Electric Code), ATEX Low Voltage criteria, ATEX Machinery Directive, CSA

(Canadian Electric Code), CCOE

(Chief Controller of Explosives) in India,

GHOST in Russia among others. If required, the turbines will be wired to satisfy

intrinsically safe (IS) wiring methods as well as providing purged enclosures and

barriers.

Dresser-Rand wiring protection standard for electrical packaging is using conduit.

D-R can provide armored cable and tray for a cost adder.

O.4

Electrical Maintenance

O.4.1

Routine maintenance

It is the customer’s responsibility to carry out the routine maintenance per the

Dresser-Rand maintenance manual.

O.5

Electrical Packaging

O.5.1

How wiring is marked, protective conductor marking

Wiring is marked using electrical schematic drawing component tag numbers with

permanently embossed wire markers of heat shrinkable sleeve slip on type labels at

each end of the wire. If customer tag numbers are required, these labels are

installed on each conductor in addition to the Dresser-Rand label markers. The

258

terminal numbers to which the wires are terminated to are always provided on the

wire marker.

See Figure O-1 of a typical electrical schematic showing the wiring marker

information and termination methods. The wire markers are to be used from the

information in the bubbles (D-R standard tag number) as well as customer tag

numbers (located adjacent to D-R tag bubbles) if provided. Customer wiring is

shown as dotted lines.

Figure O-1 Typical Electrical Schematic Tag Numbers for Wire Marking

O.5.2

Control devices labeled

Control devices such as trip valve test pushbuttons and emergency stop buttons are

labeled with descriptive nameplates mounted on the housing of the operator

spelling out their specific function. If the customer has tag numbers, these are

included as a separate label or included in the wording of the label. See Figure O-2

for the detail of the tags indicated on the electrical schematic.

259

All wiring shall be terminated in centrally located junction boxes. Wiring in the

boxes shall be run and laced together in an orderly fashion with all nylon tie wraps

from where it leaves the conduit bushing to where it connects in the terminal box.

Here is a list of electrical components which have resistance loads and therefore

power consumptive heat can be generated. Calculations are analyzed to insure that

enclosures are selected in a large enough size to dissipate excess heat generated

from housing electrical components.

COMPONENT

WATTAGE

Peak 150 governor

38 Watts

Solenoid dump valves

36 Watts

Tachometer

15 Watts

Magnetic pickup

50 Watts

Electro-pneumatic actuator

5 Watts

TABLE O-1 WATTAGES OF ELECTRICAL COMPONENTS USED ON SST

From this table it is demonstrated that there are minimal thermal loads being added

to the overall thermal contribution from the electrical components used on SST

turbines.

O.5.4

Materials of conduit and how supported

Dresser-Rand’s standard for wiring protection is to use rigid galvanized steel

conduit supported with Unistrut installed on the baseplate, if provided. See figure

O-2 section O.5.9 for a graphic example of conduit routing on a baseplate.

All conduit runs are are to be a minimum of 10” distance from all steam lines and

steam casings, both horizontally and vertically.

Liquidtight (flex conduit) shall be used for connections to all equipment where

adjustments or vibration requires flexible connections. Maximum length of the

Liquidtight is 36”. Internal grounding wires are provided when applicable from the

device to the grounding bar installed inside the junction boxes.

O.5.5

Percentage fill of conduit

All wiring for the SST turbine does not exceed the minimum percentage fill limits

per the sizes of conduit applied.

O.5.6

Procedure to protect wiring when shipped loose

If electrical components are to be shipped loose, the wiring from the turbine to the

component will be coiled up with protective wrapping applied to the coils. The

wiring markers are installed on the wires for determination of connection to the

correct termination point per the electrical schematic and layout drawings

associated with the contract.

261

O.5.7

Terminal head drawing

Figure O-3 is of a standard supplied ¾” terminal head which typically are installed

on limit switches, solenoid valves, magnetic pickups and other electrical

components which do not have their own wiring termination protective hardware.

Figure O-3 Standard ¾” Terminal Head

O.5.8

Wiring into J-box

Junction boxes shall be arranged for side or bottom entry only. Top entry is not

allowed. Conduit unions shall be provided to facilitate replacement or removal of

instruments and junction boxes.

Seals are provided for wiring entrance into all enclosures if the hazardous area

classification requires them.

Hubs are installed into the bottom of the enclosure for Dresser-Rand electrical shop

wiring entrance. Customer connections are left for field installation unless

customer requests hub installation at the factory.

Vents and drains are provided in the top and bottom of the enclosures to allow

moisture from condensation to be drained. The drains and vents are specified in

accordance with the level of protection provided with the enclosure.

262

Dresser-Rand incorporates Crouse-Hinds and Hoffmann enclosures unless there are

customer requirements for other suppliers. At a minimum the enclosures are 304

Stainless Steel with NEMA 4X ingress protection ratings.

Here is a description of the ATEX-certified (NEXT) Crouse-Hinds enclosure gasketing:

Features include thirteen basic sizes in two standard depths to optimise the

accommodation

rail-mountable

terminals

components.



Fully removable lid, concealed hinges provide 180° opening



Lid fixing, two or three stainless steel captive screws on one side



Lip on upstand increases gasket contact area, ensuring high degree of ingress protection



Internal / external earth stud



40mm wide fixing lugs for assembly on standard frames



Option of 0, 1, 2, 3 or 4 gland plates with earth stud



One piece gasket on lid and gland plates



Padlock hasp available as additional accessory

The retained stainless steel slotted hex bolt fastenings provide a rapid means of

achieving high integrity ingress protection

(IP) of

66 for reliable & rapid

environmental protection. The high integrity

“single piece” sealing gasket for

superior ingress protection

(IP) of

66 and excellent recovery and re-sealing

properties for continuous environmental protection. An integral drainage channel

prevents liquids or other solids contaminates from running in or falling into the

enclosure when the door is opened, and to minimize gasket path contamination. An

integral external & internal feed through brass earth / ground stud assembly enables

rapid and reliable protective earth / ground connection mounted on the side of the

enclosure for ease of access.

Here is a description of a Hoffmann ATEX certified enclosure:



Easy-to-use Type 316 stainless steel quarter-turn door latching



3-mm double-bit insert for security



Slot and through-hole side-mount hanging brackets



Lift-off door hinges



Fabricated from Type 316 stainless steel



Type 316 stainless steel external fasteners



Gray silicone high-temperature gasket on doors and gland plates

Internal/external brass earth/ground provision

263

Figure O-5 Example

of conduit routing, non-typical application

O.5.10

Details of neutral conductor

On the Dresser-Rand electrical schematic the conductor information is provided in

the notes section of the drawing.

O.5.11

Drawing stating markers for terminals and conductors

Dresser-Rand’s standard electrical schematic states the terminal type and

manufacture on the enclosure sheet of the schematic. Conductor data is located in

the notes section of the electrical schematic drawing, providing manufacture and

conductor part number data.

O.5.12

Drawing showing how cover plates are tied into bonding

265

On the Dresser-Rand electrical schematic/layout drawings the details of the

enclosure are provided with notes on gounding and bonding of components.

O.5.13

Drawing showing how protective bonding cross-sectional area of

circuit conductors.

Maximum impedance for protective bonding. Details of the circuit conductors are

provided in the notes section of the electrical schematics.

O.5.14

CE listed components are wired per manufacturer’s instructions.

Testing of component wiring per CENELEC EN60204-1 standards and data are

recorded on FAT form.

O.5.15

Prevention of touch voltage

Testing of touch voltage test limits per CENELEC EN60204-1 standards and data

recorded on FAT form.

O.5.16

Electrical shock hazard warning

There are electrical shock hazard warnings attached to the turbine per CENELEC EN60204-1

standards and the verification data is recorded on FAT form that all applicable drawings are

showing correct warning placement.

O.5.17 Peak starting currents and permitted voltage drops.

The electronic governors are capable of riding out minimal electrical supply

disturbances

O.5.18

Confirmation of use of SST electrical components:

Temperature