DTEC Ltd.

GFMIV

Ground Fault Monitoring

And Interruption System

This manual should be read thoroughly before installing this instrument. This instrument has been tested thoroughly by the manufacturer and meets or exceeds several standards, however the instrument has not been implemented in field use for a long history. Therefore; the manufacturer cannot be held liable for any situations that may arise with use of this instrument. It is essential that the instrument is connected, tested and properly maintained for correct operation. In any situation where possible injury or damage may arise, continuous monitoring and sensible actions must be taken.

CONTENTS

1.0 Ground Fault Monitor and Interruption Manual............. 4

1.1 Introduction:.............................................................................................. 4

1.2 Specifications:.......................................................................................... 4

2.0 Installing GFMIV............................................................ 5

2.1 General Information................................................................................. 5

2.2 General Operation:................................................................................... 5

2.3 Lid Top Connections:............................................................................. 5

2.3.1 Relay Common and Normally Closed Terminals:..................... 6

2.3.2 Sense Circuit Terminals:............................................................. 6

2.3.3 Chassis Reference:..................................................................... 6

2.3.4 Input Power Connection:............................................................. 6

2.3.5 Reset Circuit:................................................................................ 7

2.4 Options:...................................................................................................... 7

2.4.1 Channel Indication Lights (Option):............................................ 7

2.4.2 Channel Select Rotary Switch (Option):.................................... 7

2.4.3 Panel Meter (Option):.................................................................. 7

2.5 Sense Blocks:........................................................................................... 8

3.0 Lid Top Connections..................................................... 9

Appendix A Circuit Drawings.............................................. 10

Fig. 3. Sense Block Wiring........................................................................... 10

Fig. 4. System Block Diagram..................................................................... 10

Fig. 5. Ground Fault Monitor Wiring Diagram For I.H.S........................ 11

Fig. 6. Ground Fault Relay Board Schematic......................................... 12

Fig. 7. Ground Fault Monitoring Board Schematic................................ 13

Appendix B GFMIV Setup Procedures............................... 14

Appendix C Trouble-Shooting............................................. 19

Power Failure................................................................................................... 19

Output Relay Circuit....................................................................................... 19

Override Condition......................................................................................... 19

1.0 Ground Fault Monitor and Interruption Manual

1.1 Introduction:

This document contains setup, wiring diagrams and an overview of the operation for the GFMIV Ground Fault Monitoring and Interruption System. The ground fault system is intended to protect equipment and people from failure or injury. The system provides the interruption of a faulty circuit by means of "opening" the path to a contactor or switching device. The system also measures and indicates the amount of "leakage" voltage to the reference chassis ground if equipped with this option.

1.2 Specifications:

Mechanical:

Dimensions: 7.09" wide x 5.00" height x 10.00" deep.

Weight: 5 lbs.

Electrical:

Power input: 84-264 Vac @ 60 Hz @ 2 amps.

Fuse: 250 Vac @ 2 amps AGC.

Number of circuits: 4 individual sense circuits.

Monitored circuits: 5 to 2000 Vdc and/or 110 to 3000 Vac 1 or 3 phase.

Interruption point: Factory set 500 Kohms.

Output Relay: 240 Vac @ 10 amps Note: No DC is allowed to be switched.

2.0 Installing GFMIV

2.1 General Information

Installation of the ground fault monitoring system requires the connection of the input Ac power, chassis reference, relay output circuits, reset circuit and sense inputs to the correct sense blocks. These sense blocks are different for 1 phase/dc circuits and 3 phase circuits. The sense blocks are installed between the monitored circuit and the sense inputs on the lid top. The typical connections for these blocks are in Appendix A.

The relay outputs are triac switches that open upon a ground fault condition. Typical installation is to connect the coil of a contactor through this relay and hence be disconnected if a ground fault condition arises. Ac voltages are only allowed to be connected to relay output circuits due to the triac solid state relays.

2.2 General Operation:

The operation of this ground fault system is to interrupt an electrical circuit if there is a resistance of 500 Kohms between a conductor and chassis ground. The channel with the ground fault will illuminate an LED on the front of the GFIV1.0 board. This is visible through the translucent lid of the box. The LED will only illuminate while the ground fault is present, if the circuit has been interrupted and the source of the problem has been disconnected the LED will not illuminate. The interruption of the circuit is provided by connecting a path through a triac relay output and energizing the relay under normal operating conditions. If a fault arises the relay will de-energize interrupting the path and isolate the circuit. See Appendix A for typical connections to a circuit.

2.3 Lid Top Connections:

The lid top has connections for 4 - Relay Common Terminals, 4 - Relay Normally Closed Terminals, 4 - Sense Circuit Terminals, 2 - Chassis Reference Terminals, 2 - Reset Terminals and AC input power. The block diagram and examples for the lid top wiring is located in Appendix A.

2.3.1 Relay Common and Normally Closed Terminals:

The ground fault system can monitor up to 4 independent AC and/or DC circuits. Each circuit has a solid state relay with a triac output that can interrupt the corresponding channel if a ground fault condition appears. Typically the Relay Common will connect to a power source (line) that enables a contactor or switching device. The Normally Closed will connect to one side of the coil or switching device. If no ground fault condition is present the path will be completed by the solid state relay closing. If a ground fault condition is present the path will be interrupted by the solid state relay opening. See wiring example in the drawing appendix A.

2.3.2 Sense Circuit Terminals:

The sense circuit inputs should be connected directly to the sense blocks via a 22 to 20 gauge wire. The sense blocks are then connected to the monitored circuit. See appendix A for connection to circuits. An external capacitor must be installed to each sense circuit monitored to provide stable circuit operation and optimize response time. After thorough testing a .047uF capacitor provides the fastest response time with stable circuit operation. The capacitors should be installed in each circuit monitored, between the sense line input and the chassis reference terminals.

2.3.3 Chassis Reference:

The chassis reference input is essential for proper operation of the ground fault system and must be connected to the system chassis ground or chassis ground to be referenced. Typically this is the chassis ground of the hull, umbilical, rack etc. The 2 terminals are tied together inside the unit so connection of either terminal will be correct. If this terminal is not connected to chassis ground the ground fault system will not function correctly.

2.3.4 Input Power Connection:

The input power of 84-264 Vac 60 Hz @ 2 amps must be stable and protected if possible for proper use. The power supply contains a fuse rated for system operation and this is the only fuse associated with the system. Spares are recommended (250Vac @ 2amps AGC).

2.3.5 Reset Circuit:

The reset circuit connections found on the lid top terminal block should be connected to a normally open, momentary push-button switch. When the reset button is depressed all 8 channels on the solid state relay board will be reset to the normally closed position assuming it has been interrupted. If the ground fault that caused the interrupt has been repaired or corrected the reset button is depressed to resume proper operation, if it has not been corrected the solid state relay will remain "open". While the reset button is being depressed it is possible to "override" the relay output and force it closed. Operators must be aware of this state as you could override an interrupted circuit and cause possible damage or harm.

2.4 Options:

The following options could be implemented in the I.H.S. customized ground fault interrupter. These implementations would require significant modification to the existing enclosure and connections.

2.4.1 Channel Indication Lights (Option):

An illuminated red light indicates that the ground fault level of that channel has reached 500 Kohms or below and the circuit has been interrupted. The channel light will stay interrupted until the reset button is depressed and the light goes off. If the light does not go off when the reset button has been depressed then the channel still has a ground fault present and should be checked more thoroughly.

2.4.2 Channel Select Rotary Switch (Option):

The rotary switch selects which analog value is displayed on the analog panel meter. The switch can be rotated to any of the 8 sensed circuits and the corresponding resistance value of that circuit will be displayed on the panel meter.

2.4.3 Panel Meter (Option):

The panel meter displays the resistance value of the circuit selected. The panel meter will peg over hard to the infinite side of the scale because when at infinite resistance the output of the control board is slightly negative.

2.5 Sense Blocks:

A sense block is required for each channel to be monitored and sense blocks may vary from circuit to circuit due to the type of circuit to be monitored. It is essential that the proper sense blocks are used in each circuit or incorrect and faulty readings could result. The input resistance the sense circuit requires for proper measurements is 600 Kohm, therefore; in a DC or 1 phase AC circuit the 2 resistors must be 1M2. In a 3 phase AC circuit the 3 resistors must be 1M8. For monitored circuits up to 1000 volts use 1/4 watt resistors, for monitored circuits up to 2000 volts use 1/2 watt resistors and for monitored circuits up to 3000 volts use 1 watt resistors. Try to keep the sense blocks close to the circuit being monitored for safety reasons and use 22 to 20 gauge wire for the sense wire to keep the wires impedance low. For connection examples see appendix A.

3.0 Lid Top Connections

Appendix A Circuit Drawings

Fig. 3. Sense Block Wiring

Fig. 4. System Block Diagram

Fig. 5. Ground Fault Monitor Wiring Diagram For Hardsuits.

Fig. 6. Ground Fault Relay Board Schematic

Fig. 7. Ground Fault Monitoring Board Schematic

Appendix B GFMIV Setup Procedures

Circuit description:

The DTEC Ltd. GFMIV ground fault monitoring board places a high impedance (~2M2 ohms) voltage source of +25.6 VDC, with respect to chassis ground, onto eight channels. It then measures the drop across sensing resistors. These sensing resistors are found installed on the DTEC GFM-3 termination board. These resistors are 1M2 ohms. If a ground fault condition is developing this +25.6 vdc level decreases. If +25.6 VDC is measured with respect to chassis ground on the monitored channel there is no ground fault. As the this voltage drops, a corresponding decrease in the ground fault resistance level and an increasing analog output voltage for that channel are produced.

There are 5 sections to the circuit board:

Power Supply - The 2 - DC-DC converters receive a logic +15 vdc and output +/- 15 vdc. These work in series to create a +60 vdc circuit and a single +15 vdc with respect to chassis ground.

Voltage Comparitor - This section compares the trip level (set by Pot 11 and measured on test point 1) to the measured sense input level.

Digital Output - This section triggers the digital output to be enabled. This level is either active high (+5 or +15c vdc) or active low (0 vdc). The active high/low is selectable by Jumper 1 (JP1). No matter what the state of JP1 the LEDs on the board with only illuminate if the ground fault trip level is reached.

Analog Output/Isolator - This section outputs 1 value as selected by the bit select inputs. ( C12, C14, and A14). The output is isolated and measured with respect to logic ground and should range from +0.62 to +5.00 vdc.

Bit Select Input - This is the section which selects the channel that will be routed through the analog isolator and is outputted to the telemetry system. The following is a table for the bit select levels and the corresponding channel to be routed to the analog output.

Bit Select Input Terminal Level

Monitored C12 (lsb) C14 A14 (msb) Edge Connector

2 3 4 Termination Card

1 1 1 1

2 0 1 1

3 1 0 1

4 0 0 1

5 1 1 0

6 0 1 0

7 1 0 0

8 0 0 0

**note**

lsb - Least Significant Bit

msb - Most Significant Bit

0 - Logic Ground

1 - Logic +15 vdc

Board Setup

The ground fault board is set up at the factory to measure ground faults ranging from 100 M ohms to 0 ohms. For further adjustments or re-tuning follow these instructions.

No foreign wiring should be connected to the board only the essential wiring.

Connections for the board:

Edge Termination Board Description

Connector Connection

C2 39 Chassis Ground

C4 38 Logic Ground

C10 1 Logic +15 vdc

C12 2 Bit Select 1 (lsb)

C14 3 Bit Select 2

A14 4 Bit Select 3 (msb)

C16 5 Digital Output Alarm For Channel 1

C18 6 Digital Output Alarm For Channel 2

C20 7 Digital Output Alarm For Channel 3

C22 8 Digital Output Alarm For Channel 4

A16 9 Digital Output Alarm For Channel 5

A18 10 Digital Output Alarm For Channel 6

A20 11 Digital Output Alarm For Channel 7

A22 12 Digital Output Alarm For Channel 8

C24 37 Analog Output

C26 13 Channel 1 Input Sense Line With External Resistors

C28 14 Channel 2 Input Sense Line With External Resistors

C30 15 Channel 3 Input Sense Line With External Resistors

C32 16 Channel 4 Input Sense Line With External Resistors

A26 17 Channel 5 Input Sense Line With External Resistors

A28 18 Channel 6 Input Sense Line With External Resistors

A30 19 Channel 7 Input Sense Line With External Resistors

A32 20 Channel 8 Input Sense Line With External Resistors

** Note you must use external sense resistors when using inputs 13 to 20

Test points used on the board:

- Input logic voltage level point and ground point found in the rear left corner.

- Chassis ground point found near LED 8

- TP1 found near power LED9 and C18

- TP3 found near C19 and P10

Setup

Tune Pot 11 (P11) so the voltage at Test Point 1 (TP1) is +5.65 vdc with respect to chassis ground. This calibrates the digital output trip level to activate at ~500K ohms.

Tune Pot 10 (P10) so the voltage at Test Point 3 (TP3) is +5.00 vdc with respect to chassis ground. This value will have to be adjusted later.

Tune Pots 1 through 8 (P1 to P8) so the voltage at the junction of the diode and capacitor is +10.00 vdc with respect to chassis ground. For example to set up channel 1:

- place the "+" ve probe of multi-meter on the junction of D1 (diode 1) and C1 (capacitor 1) and the "-" ve on the chassis ground.

- tune P1 until the multi-meter reads +10.00 vdc this happens near the very end of the pot.

Eg. To setup channel 4:

- place the "+" ve probe of multi-meter on the junction of D4 (diode 4) and C4 (capacitor 4) and the "-" ve on the chassis ground.

- tune P4 until the multi-meter reads +10.00 vdc this happens near the very end of the pot.

** Note ** The channel being setup can't be calibrated if it is selected by the bit select inputs. This is because of the extra circuitry that is connected when the channel is selected loads down the signal slightly.

eg. If channel 1 is being setup the bit select inputs can't all be on (1,1,1)

If channel 4 is being setup the bit select inputs can't be off,off,on (0,0,1)

If channel 8 is being setup the bit select inputs can't all be off (0,0,0)

It is best to set the bit select inputs C12,C14 and A14 all low (0,0,0). Setup each channel and when you prepared to setup channel 8 change bit select 1 - C12 high (1). Now setup channel 8.

Tune Pot 9 (P9) so with a 5M0 ground fault (with the sense resistors in the circuit) the analog output value is +0.620 vdc with respect to logic ground.

This only needs to be done once because its the same for all channels.

Eg. - place a wire on terminal 13

- input bit selects should all be on (1,1,1) so channel 1 is selected to be routed through the analog isolator.

- place a 5M0 ohm resistor between chassis ground 39 and channel 1 input sense lines 35 or 36 ( they should be tied together).

- place the "+" ve probe of the multi-meter on the analog output 37.

- place the "-" ve probe on the logic ground point or 38.

- tune P9 until the meter reads +0.620 vdc

Tune Pot 10 (P10) so with a 0 ohm (short to chassis ground with the sense resistor in the circuit) the analog output reads +5.00 vdc.

Eg. - place a wire on terminal 13

- input bit selects should all be on (1,1,1) so channel 1 is selected to be routed through the analog isolator.

- place a wire between chassis ground 39 and channel 1 input sense line 13

- place the "+" ve probe of the multi-meter on the analog output 37.

- place the "-" ve probe on the logic ground point or 38.

- tune P9 until the meter reads +5.00 vdc

Selectable features:

Jumper 1 JP1 - This selects the digital output from either active high or active low level.

Jumper installed is active low. Jumper removed is active high.

+5 vdc or +12 vdc - This is a hard wire jumper - JP3 - found in front of P11. If the jumper is between the center and left points the digital output level is +5 vdc. If the wire jumper is between the center and the right points the digital output is +12 vdc.

Oceaneering Gespac systems are active high with +5Vdc selected for the digital output level.

IOS Siemens systems are active high with +12 vdc selected for the digital output level.

Appendix C Trouble-Shooting

Power Failure

check input Ac power into the unit.

check fuse in power supply inside enclosure.

check wall breaker.

check to ensure that internal power supply is set to 15 Vdc

Output Relay Circuit

check wiring connections on solid state relay board.

check resistance of relay n/c and relay common terminals (should be <3 ohms).

check for power supply voltages on both control boards.

check other channels for improper operation.

check the reset circuit for proper operation. (energize (+15Vdc) to reset)

check LED on front of GFIV1.0. If led is on, relay should open.

Override Condition

an override condition can be caused by depressing and maintaining the reset switch. This is not recommended as serious harm may result to equipment and/or humans.

Please call DTEC for support if the above information doesn't correct the problem.