Technical Description of SCR System

  1. SCR Drive and Control Unit

H2000 SCR equivalent with module1400. Each H2000 SCR unit will contain the following:
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A1Merlin-Gerin MasterPact 1600 AF/1600AAT input switch UV trip

2NO/2NC auxiliary contacts Fixed mount

B1DC Voltmeter, scaled 0-1000 VDC
C1DC Ammeter, scaled at 0-2000 ADC
D1“SCR ON” indicating lamp, (green)
E1SCR type, six (6) element, two (2) quadrant, rated at 1800 ADC continuous at 750 VDC

The bridge will be vertically configured and cooled by a single blower. It shall be protected using semiconductor type fuses.

F1DC Control Module Contain the Following:

6 pulse thyristor firing circuits with “hard firing” outputs. The synchronizing signal originates directly form the AC line.

High speed current regulators with twenty millisecond response Automatic current limit load sharing for motors driving the same shaft and driven by separate armature supplies. No setup or adjustment required.

Individual control of current limit for all drilling functions. The operator adjustable rotary torque limit potentiometer will be mounted in the driller’s console.

Motor speed regulators for the Drawworks, mud pump and rotary table. Each regulator will be interlocked with its related assignment contactor. All controls are designed to be “foolproof”. No preset sequence of operation is required. The operator may push any button at any time and the system will either follow when it is safe or block the command if it is not consistent with the operation.

Manual voltage control for maintenance operation.

Thyristor gate suppression at approximately 150% of the bridge rating. “Zero Throttle Interlock”, the throttle on the drillers console must be

  returned to zero after an assignment change before the motor can be powered.

Module Fault Finder includes a meter and a switch mounted on the front of the module for monitoring all critical internal voltages.

Drawworks dynamic brake control circuit.

G11 Set of DC contactors to allow for multiple assignment of the bridges
H1Surge Suppression System used to clamp any transient voltage spikes, which would be damaging to the SCR devices. Consist of a set of fused metal oxide varistors (MOVs) and will include a “Surge Suppressor ON” lamp (green).
  1. Engine-generator Control Unit

H2000 SCR equivalent with module1400. Each H2000 Eng/Gen Control unit will contain the following:___________________________________________________________________________

A1Power circuit breaker – 2000AF/2000AT, 600 Volt, 3 pole, 65 KAIC, UL/CSA rated (Merlin Gerin Masterpact)

Long time/instantaneous trip unit

Manually charged, electrically closed

UV trip unit

2NO/2NC auxiliary contacts Fixed mount

B1Instrumentation and controls Ammeter, scaled at 0-2000 AAC Kilowatt meter, scaled at 0-2000 kW Kilovar meter, scaled at 0-2000 kVAR Generator hour meter(imported)

Engine control pushbutton, “Off-Idle-Run”

Generator “Run” indicating lamp (white)

Generator “On Line” Indicating lamp (red)

Circuit breaker “Push to Close” lighted pushbutton Manual engine “Speed Adjust” potentiometer Manual “Voltage Adjust” potentiometer

C1Solid State Control Module include following:
  Voltage regulator

Working temperature range, -30 to +50 degrees C No load to full load regulation of +/- 1%

Response time of one (1) second typical

The load on any one (1) generator shall not differ more than +/- 10% of its rated kilowatt load from no load to full load

Reactive Power is shared between Generators by reactive power droop compensation

Real power is shared by a master / slave command line

Exciter power supply, 12 amp maximum current (the exciter current limit is set to suit the individual exciter)

Exciter power supply maximum voltage is 240 volts ( this is set by the choices of the exciter transformer and the generator self excitation requirements)

Protective functions built into the regulator are:

Reverse power trip set at -7%

Under frequency trip set at -10%

Overvoltage trip set at 15%

Overspeed trip set at +10%

Electronic governor

Frequency/voltage scheduled for engine operation at idle speed Speed regulation from no load to full load of +/- 1 Hz steady state Response time on 0.8 seconds typical

Maximum load unbalance between engines (one hot, one cold) at all points, no load to full load, +/- 5% of its rated load

Governor electronics arranged for battery power to advance throttle for “black start” capability.

  1. Generator Synchronizing System

The Generator Synchronization (Sync) Circuit is required to connect additional generators to the Main AC bus, after one (1) or more generators are already connected to the Main AC Bus. The Sync Circuit compares the frequency and voltage of the Main AC Bus with that of the generator being brought on line, so that they can be matched before the new generator’s circuit breaker is closed. All of the online engine-generators’


  1. 600v Main Bus Ground Fault Detection System

The Ground Fault System is designed to detect AC ground faults via a set of wire connected grounding resisters. A Ground Test Pushbutton is included for determining if a Ground Fault indication is actually a burned out lamp.

A1AC ground ammeter scaled at 0-100%
B1DC ground ammeter scaled at -100-0-100%
C3Ground detection light
D1Test pushbutton

load will share automatically. Auto synchronizations circuit will require auto speed adjustment. The Generator Synchronizing Circuit will include the following:

A1Synchroscope scaled at fast-slow
B1Voltmeter scaled at 0-750 VAC
C1Frequency Meter scaled at 55-65 Hertz
D1Sync selector switch
E2Synchronizing lamps
F1Sync check relay
  1. MCC Ground Fault Detection System

One (1) set MCC Ground Fault Detection System is for 480 volt MCC system. The Ground Fault Detection System is designed to detect ground faults via a set of wire connected grounding transformer; three (3) ground detection light will indicate the ground phase.

  1. Hands-Off-Cranking Circuit(HOC)

The Hands-Off-Cranking (HOC) Circuit allows starting of the first engine when no other power source is available. The circuit provides power to the AC Control Module’s “engine starting and pulse pickup” circuits via two (2) 12 Volt batteries. The Hands-Off-Cranking Circuit is connected to all Gen Control Cubicles via the Generator Interconnect Terminal Block located in each cabinet. In addition, there will be a small

4GENx3MP Proposal                                                 page 7 of 17                          Proposed by HHCT


rectifier taking power from the auxiliary generator and supply the required DC power to

start the engine in the black out condition.
A1Set of CPT’s
B1Set of fuse
C1Single phase diode bridge
D212V batteries
  1. Power Limit Circuit

The Power Limit System will monitor the kW engine loading the KVA generator loading of each engine/generator set. If any of these parameters reach their limits, the Power Limit Circuit will reduce the power being delivered to the loads so that the load on each generator is held at its limit until the loads on the SCR drives are reduced to a level below the generator limit. Percent Power Limit is indicated by a meter on the Drillers Console. Amber warning lamps are illuminated on the front of the Drillers Console at a load level just below the power limit.

  1. Mud Pump Over-Speed Protection

The Sprocket Slit Circuit provides over speed protection when two (2) motors are paralleled on a single Mud Pump and driven from the same SCR Bridge. If either of the two (2) motors exceeds a preset limit, the Sprocket Slip Circuit will remove power from both motors by opening the DC assignment contactors.

A lighted pushbutton is provided on the front door of the system. The lamp indicates an “over speed trip” and the pushbutton is used to reset the circuit after the over speed trip has been corrected. The Sprocket Slip Circuit compares the current drawn by each DC motor using a “Hall Effect Device” which is mounted between the DC contactor and the motor. The Sprocket Slip Circuit compares the current to the voltage output of the SCR Bridge to determine if an over speed condition exists.

  1. Drillers Console

The console will be constructed of 12 gauge 304 stainless steel. The throttle hand wheels will be of solid stainless steel and shall provide 100% back up of the throttle function. The console will be water tight with a gasket door. The console will be acceptable for use in a Class 1, Division II area, by means of a Z Purge system in accordance with NFPA 496, when attached to an external dry air supply of 85 to 150 psi. Communication between PLC cabinet and the drillers console will be via special communication cables. Cables enter the bottom of the console via plugs and receptacles.

A5Mud Pump 1 Hand Throttle Mud pump 2 Hand Throttle Mud pump 3 Hand Throttle

Drawworks Hand Throttle Rotary Table Hand Throttle

B7SCR Assignment Switch Mud Pump 1 “Off/On” Switch Mud Pump 2 “Off/On” Switch Mud Pump 3 “Off/On” Switch Drawworks “Forward/Off/Reverse” Switch Rotary Table “Forward/Off/Reverse Switch PLC Bypass Switch
C6Rotary Table Ammeter Percent Power Limit Meter Mud Pump 1 Ammeter Mud Pump 2 Ammeter Mud Pump 3 Ammeter Drawworks Ammeter
D17Generator 1 On Lamp(Amber) Generator 2 On Lamp(Amber) Generator 3 On Lamp(Amber) Generator 4 On Lamp(Amber) SCR 1 On Lamp(Amber)

SCR 2 On Lamp(Amber)

SCR 3 On Lamp(Amber)

SCR 4 On Lamp(Amber)

SCR 5 On Lamp(Amber) Purge Loss Lamp(Red)

Power Limit(ember)

Ground Fault(Red)

  Mud Pump 1 Aux. [ Amber ] Mud Pump 2 Aux. [ Amber ] Mud Pump 3 Aux. [ Amber ] Drawworks Aux. [ Amber ] Rotary Table Aux [ Amber ]
E4[ Emergency SCR Shutdown ]

[ Emergency Engine Shutdown Pushbutton ]

Purge Loss Alarm Silence and Lamp Test Pushbutton Acknowledge Pushbutton

F1Rotary Table Torque Limit Potentiometer
G1PLC remote I/O
H1Type Z Pressurization System
I1 LotPlugs and Receptacles
  1. Foot Throttle

The Foot Throttle is constructed of 12 gauge 304 stainless steel, built to with stand the environment normally encountered on the rig floor. It includes dual stainless steel return springs to provide a fail-safe return to the minimum position in the event of a single spring failure. Provisions for dry air connection are also included. The foot throttle connects directly to the drillers console through a three-wire connection.

  1. Drawworks Dynamic Brake

The Drawworks Dynamic Brake will slow the Drawworks motor from full speed to some preset speed within 8 to 10 seconds after the foot throttle is released. The power generated by the free wheeling DC motor is then fed into a stainless steel grid resistor bank. During normal operation of the Drawworks, the dynamic brake is non-operative. If at any time, the motor speed is higher than the Drawworks throttle setting and the foot throttle is not in use, the dynamic brake will operate.

  1. 600 Volt Feeder Circuit Breakers Section
11Merlin-Gerin MasterPact Circuit breaker for 1250kVA MCC transformer 1600AF/1600AT,600V, 3P, 65kAIC,fixed mount
21Merlin-Gerin MasterPact Circuit breaker for TD 1250AF/1250AT,600V,
  3P, 65kAIC,fixed mount

MCC transformer feeder breaker located in the Generator 2 cubicles. Top drive feeder circuit breaker located in the Generator 1 cubicles.

  1. Transformer Section

The transformer is used for power supply for MCC and lighting. The technical data is

shown below:

11Copper Wound, Dry Type. 1250kVA, 600:480 V AC,3 Ph, 60 Hz, Del: Wye , MCC transformer
11Copper Wound, Dry Type. 112.5kVA, 480:120/208 V AC,3 Ph, 60 Hz, Del: Wye , Lighting transformer
  1. 480V Motor Control Center

The MCC will be US NEMA ICS2 standard and GCS type cubicle, wired 480 Volt, 60 Hz, with individual breakers. The horizontal bus will be tin plated copper and 1000 amps rated. The vertical bus will be tin plated copper and rated for 300 amps. A copper ground bus will run the full length of the MCC line up. Each starter will be complete with a 480:120 control power transformer fused on the primary and secondary (magnetic only) breaker, a contactor and an electronic overload relay. Red run indicating light.

Legend :

HOA= Hands-Off-Automatic Control 2WRC = Two (2) Wire Remote Control PBSS= Pushbutton Stop/Start 3WRC= Three (3) Wire Remote Control AF/AT= Amp Frame/Amp Trip FVNR= Full Voltage Non-Reversing

480Volt MCC

115HPHOAMud pump 1 liner wash
215HPHOAMud pump 2 liner wash
315HPHOAMud pump 3 liner wash
4115HPHOAMud Pump 1A blower
5115HPHOAMud pump 1B blower
6115HPHOAMud pump 2A blower
7115HPHOAMud pump 2Bblower
8115HPHOAMud pump 3A blower
9115HPHOAMud pump 3Bblower
10115HPHOADrawworks A blower
11115HPHOADrawworks B blower
12115HPHOARotary table blower
13115HPHOADrawworks lube oil pump
151100HP3WRCMud mix pump 1
161100HP3WRCMud mix pump 2
171100HP3WRCMud mix pump 3
181100HPHOACharging pump 1
191100HPHOACharging pump 2
201100HPHOACharging pump 3
212100HP3WRCWeight pump
221100HP3WRCMud shearing pump
23175HP3 WRCSpare
241100HP3 WRCSpare


11250AF/200AT/3PLight Transformer
21100AF/70AT/3PBOP unit
31100AF/100AT/3PMud logging
61100AF/100AT/3PDog house
72250AF/150AT/3PAir compressors
82100AF/15AT/3PShale shakers
91100AF/15AT/3PAir dryer to be sized as per equipment load review
101100AF/30AT/3PUniversal owner supplied wireline unit
116250AF/200AT/3PMud Tank
141100AF/100AT/3PWater transfer pump
151100AF/100AT/3PBrake water pump
161100AF/100AT/3PFuel transfer pump
171200AF/150AT/3PRig air compressor 1
181200AF/150AT/3PRig air compressor 2
191100AF/30AT/3pEzy Torque
201100AF/70AT/3PEmalgo brake
211100AF/100AT/3PStorage house
221100AF/100AT/3PTool house
231100AF/100AT/3PDog house
  1. 208/120 Volt Lighting Panel

One (1) 42 circuit 120Y208 volt, 3 phase, 4 wire panel board. The circuit panel will be a 208/120 Volt, 3 phase, 4 wire, Panel feed from the lighting transformer

1112015AT/1PSCR house interior lighting
2112015AT/1PSCR house duplex receptacles
3112020AT/1PGenerator skid #1 lighting
4112020AT/1PGenerator skid #2 lighting
5112020AT/1PGenerator skid #3 lighting
6112020AT/1PGenerator skid #4 lighting
7112020AT/1PSolids control area #1 lighting
8112020AT/1PSolids control area #2 lighting
9112020AT/1PSolids control area #3 lighting
10112020AT/1PSolids control area #4 lighting
11112020AT/1PWater tank lighting
12112020AT/1PTrip tank lighting
13112020AT/1PFuel tank lighting
14112030AT/1PGenerator #1 heater
15112030AT/1PGenerator #2 heater
16112030AT/1PGenerator #3 heater
 112030AT/1PGenerator #4 heater
17112030AT/1PDrawworks a motor heater
18112030AT/1PDrawworks b motor heater
19112030AT/1PRotary table motor heater
20112030AT/1PMud pump 1A motor heater
22112030AT/1PMud pump 1B motor heater
22112030AT/1PMud pump 2A motor heater
23112030AT/1PMud pump 2B motor heater
24112030AT/1PMud pump 3A motor heater
25112030AT/1PMud pump 3B motor heater
28112020AT/1PPump room lighting
29112020AT/1PSearch lighting
30112020AT/1P36V Transformer
  1. System Host PLC

The System Host PLC is a high speed, versatile modular mini-PLC. The PLC is used for serial communication with remote consoles and other rig devices. Additionally, the PLC incorporates the SCR bridge assignment logic. The PLC shall consist of the following

ASiemens S7-300 Modular PLC
B32 Bit, Fixed & Floating Point CPU
CUp To 1024 Digital Inputs / 1024 Digital Outputs
DUp To 256 Analog Inputs / 256 Analog Outputs
EComplete Instruction Set With “Built-In” Functions
FBuilt-In Self Diagnostics
GSpecial Cable for Communication
  1. Power Control House

The power control house will be not more than 13500 mm long, 3000 mm wide and 3100mm high. And weigh approximately 35,000 kg.

The house will be designed for transportation by an oilfield type trailer. The frame of the house will be constructed of structural steel and continuous welded. The siding of the walls and skins of the roof will be constructed of twelve (12) gauge sheet steel. All corners shall be trimmed out by bending, and seam welding leaving no sheet edge exposed. The runners of the skid will be 45# beams, with integral cross members for a total skid height of 12.25 inches.

Three of the walls will be insulated with three (3) inch thick polystyrene block insulation. The floor and end wall with the receptacles will not be insulated. The inside surface of the walls behind the equipment will be covered with veneer of 5mm thick. The inside surface of the walls not covered by equipment will be finished with aluminum panels. A rubber neoprene mat will run the full length of the interior isle of the house.

Two (2) doors with stainless hardware will be provided. The door will open to the outside by pushing down on a “panic bar”. A %” welded eye will be put on both sides of the doors for lockout.

Two (2), seven and half (7.5) ton air conditioners will be supplied. The units will be TRANE split system type with the condenser unit (compressor and coil) will be located on an elevated rack on the porch on one end of the house. The top of the condenser unit will be no higher than the top of the house roof. The air handler unit (evaporator coil and fan) will be located with in the interior portion of the house. The hot air generated by the SCR bridges will be discharged out the top of the cubicles and re-circulated to the air conditioners via the open space between the top of the equipment and the bottom of the roof, and the cool air along a vented central duct running the length of the House.

One (1) 120Y208 volt, 3 phase, 4 wire panel board will be mounted on an interior wall for lighting and other required needs. The interior of the house will be illuminated by four (4) flush mount fluorescent lighting fixtures(2-40WRS). The 120 volt, 60 Hertz devices will be mounted in the suspended ceiling in the isle way between the SCR line-up and the MCC lineup. One (1) emergency lighting fixture with battery back up and self-charge capabilities will be provided. Two (2) 120 volt duplex receptacles will be included, one at each end of the house

Incoming power from the generators will enter the house via lugs on copper stabs through a recessed “window” located at the top and on one (1) side of the house. The windows shall be located on the same side of the house as the SCR system. DC power connections will be made using single pin connectors in the AC/DC plug panel at one (1) end of the house. DC control connections. The receptacles (100 amp and below) will be angled down at 45 degrees to relieve stress on the cables.

The house will be sandblasted and finished with a two (2) coat process consisting of an epoxy primer and a polyurethane top coat, white in color. The transformers, A/C Condenser Units and the DWDB grid box will be mounted on an uncovered porch on one end of the house.

Control wires in the SCR/generator cubicle are single conductor apparatus cable rated 600Volts or 2000Volts, AC or DC, insulated a thermosetting (cross-linked) flame retardant polyolefin, for normal operation at 125 deg C. These cables are designed for use on mobile offshore drilling units (MODU’S), aboard ships and offshore fixed platforms.

  1. Cable And Accessories

Whole set of power and control cables include:

Power and control cables in SCR house will be furnished by HHCT. DC power cable will be one (1) 535MCM every phase.

All the power and control cables out of SCR house will be furnished by customer. DC power cable will be one (1) 535MCM every phase.

All of the connector (plug and receptor) which connected to SCR house will be furnished by HHCT and made in China

  1. Technical Documentation
A5User menu(English version)
B5Customer drawing job books
  1. Training

HHCT shall provide technical training, free of charge, for up to four (4) engineers for seven (7) days at the Haier Haisi Control Technologies Company (HHCT) factory in Xian, China. The Buyer shall provide travel and living expenses for the students during training. HHCT shall provide working lunch to the students

  1. Start-up and Commissioning

HHCT shall send, at HHCT’s cost, maximum two (2) engineers to commission and start-up at customer’s rig-up yard up to twenty-one (21) days. customer is required to provide such two (2) Engineers with local transportation and accommodation. HHCT will charge on further services after such initial twenty one (21) days as


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