Material, suministros y otros

Table 3-6. DC Control Module Troubleshooting (Continued) PROBLEM / INDICATION EXPLANATION / ACTION

HAND THROTTLE REFERENCE

A. Hand Throttle does not work. A. Monitor the voltage at Pin 117 (DW) of the DC Control module while moving the Hand Throttle from one limit to the other. The voltage should vary from Zero VDC (ZERO throttle) to -8 VDC (MAXIMUM throttle).

CEMENT PUMP CONSOLE

A. Hand Throttle Reference signal missing.

A. Monitor the voltages at Pin 110 (CP REF 2) and Pin 113 (CP REF 1) of the DC Control Module while moving the Hand Throttle from stop to stop. The voltage at each Pin should vary between Zero VDC (MINIMUM) and -8 VDC (MAXIMUM). If the voltage at either pin is absent, trace the signal from the Cement Pump HAND THROTTLE rheostat.

B. Cement Pump Contactor Signal missing.

B. Monitor the voltage at Pin 112 (CP CONT) of the DC Control Module. The voltage should be +10 VDC when the SCR Circuit Breaker is open. In normal running, it will be -14 VDC when the Cement Pump Contactor closes.

This signal will only be present on the SCR Units driving the Cement Pump.

DRAWWORKS

A. Foot Throttle Reference Signal used to drive Drawworks is missing.

A. Monitor the voltage at Pin 114 (DW FT TH) of the DC Control Module while moving the FOOT THROTTLE from stop to stop.

The voltage at the Pin should vary between Zero (MINIMUM) and -8 VDC (MAXIMUM). If the voltage is absent, trace the signal to the FOOT THROTTLE rheostat.

B. Drawworks Contactor Signal not present.

B. Monitor the voltage at Pin 116 (DW CONT) of the DC Control Module. The voltage should be +10 VDC when the SCR Circuit Breaker is open. In normal running, it will be -14 VDC when the Drawworks Contactor closes.

This signal will only be present on the SCR Units driving the Drawworks.

C. Drawworks Speed Reference Signal not present.

C. Monitor the voltage at Pin 117 (DW SPD REF) of the DC Control Module while moving the Drawworks Hand Throttle from stop to stop. The voltage at the Pin should vary between Zero VDC (MINIMUM) and -8 VDC (MAXIMUM). If the voltage is absent, trace the signal from the Drawworks HAND THROTTLE rheostat.

The Propulsion Control Console ASSIGNMENT SWITCH must be set to DRILLING (if applicable).

This signal will only be present on the SCR Units driving the Drawworks.

DRILLER’S CONSOLE

A. Contactor Signal is missing. A. When SCR Circuit Breaker is closed, and DW is selected on the Driller’s Console, the signal on Pin 116 (DW) of the DC Control Module should be -14 VDC.

B. Hand Throttle On Driller’s Console is extremely sensitive.

B. With the SCR Bridge on, measure the voltage across Pins 101 (VBR+) and 102 (VBR-) of the DC Control Module. The voltage across the Pins should be 1/16 of the voltage on the SCR Bridge.

When the SCR Bridge is +750 VDC, the voltage between Pins 101 and 102 should be +46.8 VDC. Polarity of Pin 101 is + for series motors, – for shunt motors. Absence of the voltage will cause this problem.

Table 3-6. DC Control Module Troubleshooting (Continued) PROBLEM / INDICATION EXPLANATION / ACTION

C. Mud Pumps not pumping.

D. Mud Pump #1 Hand Throttle Reference Signal not present.

C. Monitor the Mud Pump Contactor Signal voltage at Pin 121 (MP2 CONT) and Pin 124 (MP1 CONT) of the DC Control Module. The voltage on each pin should be +10 VDC with the SCR Circuit Breaker open, -14 VDC with the SCR Circuit Breaker closed and the MP ASSIGNMENT CONTACTORS in this SCR Unit closed. This voltage must be present to drive the Mud Pumps.

The MP1 CONT and MP2 CONT signals are only present on SCR Units which are driving Mud Pumps.

The rig’s Mud Pump 2 may be driven from the DC Control Module MP1 inputs. The Driller’s Console MP1/2 labels will match the rig’s MP1/2 labels.

D. Monitor the voltage at Pin 125 (MP1 REF DC) and Pin 126 (MP1 REF MPC) of the DC Control Module while moving the Driller’s Console Mud Pump #1 Hand Throttle from stop to stop. The voltage at each of the pins should vary between Zero VDC (MINIMUM) and -8 VDC (MAXIMUM). If the voltage at either of the pins is absent, trace the signal to the MP rheostat on the Driller’s Console.

The Propulsion Console ASSIGNMENT SWITCH must be set to DRILLING (if applicable).

E. Mud Pump #2 Hand Throttle Reference Signal not present

E. Monitor the voltage at Pin 122 (MP2 REF DC) and Pin 123 (MP2 REF MPC) of the DC Control Module while moving the Driller’s Console Propulsion Hand Throttle from stop to stop. The voltage at each of the pins should vary between Zero VDC (MINIMUM) and -8 VDC (MAXIMUM). If the voltage at either of the pins is absent, trace the signal to the MP rheostat on the Driller’s Console.

ENGINE ROOM CONSOLE

A. Propulsion Hand Throttle Speed

Reference Signal not present. A. Monitor the voltage at Pin 118 (P REF ERC) of the DC Control Module while moving the Engine Room Console Propulsion Hand Throttle from stop to stop. The voltage at the Pin should vary between Zero VDC (MINIMUM) and -8 VDC (MAXIMUM). If the voltage is absent, trace the signal to the PROPULSION HAND THROTTLE rheostat on the Engine Room Console.

WHEEL HOUSE CONSOLE

A. Propulsion Hand Throttle Speed

Reference Signal not present. A. Monitor the voltage at Pin 119 (P REF WHC) of the DC Control Module while moving the Wheel House Console Propulsion Hand Throttle from stop to stop. The voltage at the Pin should vary between Zero VDC (MINIMUM) and -8 VDC (MAXIMUM). If the voltage is absent, trace the signal to the PROPULSION HAND THROTTLE rheostat on the Wheel House Console.

ONE OR MORE OF THE SCRS NOT FIRING

A. One or more of the six phase

voltage signals are missing. A. Check for the presence of a phase voltage signal at Pins 103 (VCA), 104 (VCB), 105 (VAB), 106 (VBA), 107 (VBC), and 108 (VAC) of the DC Control Module. If absent or low, check the fuses and ground connections.

TROUBLESHOOTING GUIDE (CONTINUED)

Table 3-6. DC Control Module Troubleshooting (Continued) PROBLEM / INDICATION EXPLANATION / ACTION

DC POWER LIMIT

A. DC Power Limit not working. A. Monitor the voltage at Pin 115 (DC PWR LIM) of the DC Control Module. The voltage should be -4 VDC for the system generators when under no load, Zero VDC when the generators are at full load. If voltage is missing or incorrect, troubleshoot the Power Limit Card located in the Generator 1 Cubicle.

PROPULSION THRUSTERS NOT DRIVING

A. Propulsion Contactor Signal not

present. A. Monitor the voltage at Pin 120 (P CONT) of the DC Control Module. The voltage should be +10 VDC with the SCR Circuit Breaker open, -14 VDC with SCR Circuit Breaker closed. This voltage must be present to drive propulsion thrusters.

The P CONT signal is only present on the SCR Units driving thrusters.

DYNAMIC BRAKE

A. Dynamic Brake Logic Signal DB

FIELD missing. A. Monitor the voltage at Pin 127 (DB FIELD) of the DC Control Module. The voltage should be Zero VAC with the SCR Circuit Breaker open, 120 VAC during the braking cycle with the SCR Circuit Breaker closed.

The DB FIELD signal is only present on SCR Units which are driving the Drawworks.

B. Dynamic Brake Logic Signal DC

CONT missing. B. Monitor the voltage at Pin 135 (DB CONT) of the DC Control Module. When braking, the voltage should be 120 VAC in SCR units assigned to Drawworks.

C. Dynamic Brake Logic Signal DBØ

missing. C. Monitor the voltage at Pin 138 (DBØ) of the DC Control Module.

The voltage should be 120 VAC in SCR units assigned to Drawworks.

ROTARY TABLE

A. Rotary Table CURRENT LIMIT

SIGNAL missing. A. Monitor the voltage at Pin 128 (RT I LIM) of the DC Control Module while varying the Driller’s Console CURRENT LIMIT rheostat. It should be between Zero VDC (50 AMPS) to -8 VDC (MAXIMUM CURRENT LIMIT). If the voltage is absent, trace the signal to the CURRENT LIMIT rheostat.

B. Rotary Table CONTACTOR

SIGNAL missing. B. Monitor the voltage at Pin 129 (RT CONT) of the DC Control module. It should be +14 VDC with the SCR Circuit Breaker open OR the SCR Circuit Breaker closed and the DC Contactors open. In normal operation, the voltage will be -14 VDC when the Rotary Table Contactors open.

RT CONT will only be present in SCR Units which are driving the Rotary Table.

C. Rotary Table HAND THROTTLE reference from Driller’s Console missing.

D. Monitor the voltage at Pin 130 (RT REF) and Pin 132 (RT REF 2) of the DC Control Module while varying the Driller’s Console Hand Throttle. It should be between Zero VDC (MINIMUM) to -8 VDC (MAXIMUM). If either/both voltages are absent, trace the signal to the ROTARY TABLE rheostat.

Table 3-6. DC Control Module Troubleshooting (Concluded) PROBLEM / INDICATION EXPLANATION / ACTION

SCR BRIDGE CT ARMATURE CURRENT FEEDBACK

A. Motor speed control not possible. A. Monitor the voltage at Pin 131 (I FDBCK) of the DC Control Module. It should be Zero VDC with the SCR Circuit Breaker open OR the SCR Circuit Breaker closed and the DC Contactors open. In normal operation, the voltage will be +2.66 VDC per 1,000 Amps out of the bridge. If this signal is missing, motor speed control is not possible.

MUD PUMP

A. The two Mud Pumps are not load sharing.

A. Monitor the voltage at Pin 133 (MP1 SLV) or Pin 136 (MP2 SLV) of the DC Control Module with SCR Circuit Breaker open OR SCR Circuit Breaker closed and DC Contactors open, the voltage at the pin will be Zero VDC (floating). In normal operation, the voltage at the pin will be 5.1 VDC per 1,000 ADC.

If voltage at the pin is not present, verify requirement, check connections, and check jumpers.

ASSIGNMENT CONTACTOR

A. Assignment Contactor Logic

Control Signal missing. A. Monitor the voltage at Pin 134 (CONT PS) of the DC Control Module. If the MANUAL SWITCH of the DC Control Module is engaged, the voltage will be +14 to +60 VDC.

PIN 109 OF THE DC CONTROL MODULE SPARE - NOT USED.

PIN 137 OF THE DC CONTROL MODULE DO NOT USE.

PIN 151 OF THE DC CONTROL MODULE SPARE - NOT USED.

PIN 152 OF THE DC CONTROL MODULE SPARE - NOT USED.

DC POWER SUPPLY

A. DC Power Supply voltage(s)

missing. A. Monitor the voltage at Pin 153 (+14 VDC) and Pin 154 (-14 VDC) of the DC Control Module. If either or both voltages are missing, check fuses F1, F2, and F3.

SCR FIRING PULSES The normal procedure in connecting the Oscilloscope is to connect the Oscilloscope GROUND lead to the CATH pin of the DC Control Module and the Oscilloscope PROBE lead to the GATE pin of the DC Control Module.

For normal running, consult Figure 3-14 (DC Regulator Circuit).

138 137 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119

Figure 3-19. DC Control Module Pinout