Le 9 th sy Movs % san i | g a a | MAINTENANCE MANUAL | HiLt GRAHAM CONTROLS HIGH WYCOMBE ENGLANDR_ SCHOOL c ONTENTS GENERAL DESCRIPTION GENERAL 1.00 INTRONUNT TON 1.01 OVERALL SYSTEM DESCRIPTION (SALVESON) 1.03 DRILLING ASSIGNMENTS (5 SCR's, 5 ASSIGNMENTS) 1.04 OC ONE-LINE (SALVESON) ELECTRICAL 1.14 SCR BRIDGE 4.14.4 SCR REPLACEMENT 1.12 GENERATOR CONTROL 1.13 SYNCHRONISING 1.14.1 MUD PUMP FIELD SUPPLY 1.14.7 FIXED VOLTAGE FIELO SUPPLY 1615 D.W. DYNAMIC BRAKE 1.16 DRILLERS CONSOLE 1.17 SURGE SUPPRESSION ELECTRONICS 1,21 OC REGULATOR 1,22 AC REGULATOR 1.23 POWER LIMIT MK IL 4.25 EXCITER SUPPLY 1.26 GROUND DETECTION 1427 SPROCKET SLIP 1,28 ACTIVE FIELO REGULATOR 1.29 PULSE PICK-UP 4.33 GROUND FAULT TRIP 41.36 HED HALL EFFECT nevIcesCONTROL LOGI 1.53 MUD PUMP CONTROL ALLATION INSTRU! 2.0 INSTALLATION INSTRUCTIONS 2.4 COOLING SYSTEM OPERATING INSTRUCTIONS 3.1 OPERATING AN ENGINE 3.2 BRINGING GENERATORS ON LINE 3.3 TO TURN ON AN SCR UNIT 3.4 RUNNING THE MOTORS TROUBLESHOOTING 44 ENGINE GENERATOR PROBLEMS 4.2 SCR CUBICLE PROBLEMS 4.3 MOTOR RUNNING PROBLEMS 4.4 SCR BLOWERS CHECKOUT PROCEDURES 5.14 AC MODULE TROUBLESHOOTING 5.12 AC MODULE BENCH CHECKOUT 5.2 AC GENERATOR CONTROL SECTION CHECKOUT 5.31 DC MODULE TERMINALS 5.32 DC MODULE BENCH CHECKOUT 5.4 SCR CHECKOUT 5.5 GOVERNOR BALANCING PROCEDURE 5.6 HANDS OFF START CHECK +0 REGULATOR MAINTENANCE SCHEDULE 6.0 DRAWINGS4,00 INTROOUCTION 4 PAGE INTRODUCTION WHAT IS AN SCR? "SCR" is the abbreviation for SILICON CONTROL RECTIFIER. First, consider a SILICON RECTIFIER (sometimes called a LICON OLODE) which is similar to a selenium rectifier or @ copper oxide rectifier, except that it is made basically from the element SILICON. A SILICON CONTROLLED RECTIFIER is made by modifying the construction of a silicon rectifier and bringing out two small "control leads” which are used to control the rectifying action of the SCR. CONVERTING AC TO DC A SILICON RECTIFIER converts AC to DC by blocking all of the negalive portions (for example) of the AC cycle and passing all of the positive portions (for example). A SILICON CONTROLLED RECTIFIER (SCR) also converts AC to DC; | but the amount of AC voltage which is converted from AC to OC may be controlled from zero to 100% using the SCR control leads.41 PAGE 2 }O_ INTRODUCTION ADVANTAGES OF AN SCR SYSTEM 1. INOUSTRIAL_USE Uses fewer engines than an equivalent mechanical or DC generator system, typically three or four engines total, sized to give the desired total horsepower. Loss of an engine does not cause the loss of any drilling functions. The total available horsepower on the line can all be channelled to one particular drilling function or spread in any desired proportions between the various functions. Brushless AC generators eliminate the downtime associated with flashovers and brush maintenance of OC generators. No auxi ry AC generator plant is required. e AC auxiliary power plus ample back-up is provided from the AC bus. OF _SCR'S SCR's have been used widely throughout the light and heavy industries including steel, paper, rubber, cement and non-ferrous meta industries since the early 1980's. E —INTRODUCTION PAGE A TYPICAL OILFIELD SYSTEM Engine | ~) AC Oe © AL bus ScR aL Z) Briggs Zy Z| AC Power for rig auxiliaries OC Traction O O Motors FICURE 1.004 An SCR system is easily the most efficient method to transfer the total horsepower available from all engines to usable work at the various variable speed shafts. Each engine drives an AC generator and the outputs of all AC generators are combined in @ common AC bus. Each SCR bridge is fed from the AC bus and so can have available to it the combined power of 311 engines on the line. The dc traction motors are fed from the SCR bridges assignment contactors,1.01 OVERALL sys: OVERALL SYSTEM DESCRIPTION The overall one line diagram for the power system for Salveson rig Dalkeith is shown in Figure 1.01A. The system consists of four 1500KW, 2640 KVA 3 phase 60Hz generators each feeding a common 600V collecting bus, The system can be operated with any number of generators running on the line and the control of each generator frequency and voltage is set individually on the door of the respective switchgear cubicle. When two or more generators are run in parallel the load sharing is forced by the electronic regulation and the left hand generator in all cases becomes the master to which the others act as slave, Five SCR power cubicles are connected to the common bus and draw AC power from whichever generators are running, converting it to DC power for driving the drilling and propulsion motors. Each SCR Bridge is fitted with OC assignment contactors which are closed in pairs (one in the positive line and one in the negative line) to feed the DC power to the drilling, propulsion or winching motors. Each SCR Bridge can be used to drive one of several different motors by selecting the correct position of the assignment switches on the Engine room Control Console or the Orillers Console. Each SCR Drive automatically selects the correct speed control function suitable for the motorPAGE 2 A_OVERALL SYSTEM that it is assigned to as soon as the main contactors are energized, and the system is fully self protecting allowing changeover of assignments without any special procedures. Two distribution transformers are connected through AC Circuit breakers to the main 600V bus. These transformers step the voltage down to 440V to feed the low voltage motors and loads of various description throughout the rig. In addition a fused breaker is used to feed one Motor Control Centre to supply power to the 600V motors on the drilling motor blowers, and the propulsion motor field supply. Detailed descriptions of the components used in this system are provided in the other sections of the instruction manual.ASSIGNMENTS 1.03(d) PAGE 4 ASSIGNMENTS The main control centre for the drilling operation is the Drillers Console usually fixed on or close to the drawworks. The main drilling assignment switch allows the driller to assign each of the SCR Bridges he has for drilling to any one of the pre-arranged programmes shown on the console engraving (a typi cal 4 SCR. @ programme switch is shown below). For convenience the programme positions are identifi das the hours on a clock defining vertically up as the 12 o'clock position, the other positions following respectively. TRIPPING DRILLING Pee eat ees (eee OFF 1] 2] 3 44 MP4) OWA | owe | RT | Lows [Mpa [MP2 | RT 1 12 2 3 4 ows | mp1] rt | owa RT jows | mp2 1 2 3 4 2 3] 4 owB | owal Rt | mp2 Dwa | RT | MP2 8 1 2 3 4 1 2 3 4 Dwe} pwaA{ mp2] Rt mei} RT| mp2 | pwa In each position (except “off” when no SCR's are assigned) the numbers in the squares refer to the SCR Bridge number 1 through 4, and the motor driven by that SCR Bridge in thet programme is shown in the box along with the bridge number. For example in the 11 o'clock position SCR Bridge No, 1 is assigned to drivo Mud Pump 1 (MP1), SCR No. Z assigned to DWA, SCR 3 to OWB and SCR 4 to RT. These are all assigned simultaneously when the main switch is in the1.03 (d) PAGE 2 DRILLING ASSIGNMENTS 11 o'clock position and all of the motors listed may be controlled independently at the same time. If SCR 1 was faulty and tripped itself off lina then the capability to drive MP1 would be lost in. the 11 o'clock position, but the other 3 SCR’s could still be used for their respective functions. In that cay if it wag essential to operate MP1 then the driller would change his assignment to say the 10 o'clock position allowing him to control MP1 from SCR 2. In that case OWB becomes assigned to SCR 1 and hence would not be available. The positions 1-4 are intended for drilling operations while 8-11 are intended for tripping, though the driller is frea t2 choose whichever he needs at any time. Positions 1 8 2 make maximum use of the available SCR’s by connecting in serias the two drawworks motors (OWS), Lhus giving full lifting torque capability but only half hoisting speed. Positions 3 & 4 give half lift capability up to full speed. During drilling the need to lift full load at full speed is limited. N.8. Only OWA will run in reverse and the dynamic braking (if fitted) only applies to DWA. loo —