A-B 1407-CGCM Combined generator control module

Installation requirements

This device is intended for overvoltage applications of category II in industrial environments of pollution class 2 (as defined in IEC publication 60664-1).

The device must be mounted vertically as it contains a heat sink. Any other mounting angle will reduce the heat dissipation capability of the device and may result in premature failure of critical components.

The device can be mounted anywhere as long as the ambient temperature does not exceed the rated ambient conditions or clearance requirements.

Clearance requirements for CGCM equipment are

- 63.5 mm (2.5 inches) of clearance is required on both sides of the unit when mounted.

- 101.6 mm (4 in.) clearance is required above and below the unit when mounted.

Electrical Connections

The connection of the CGCM device depends on the application and the excitation programme. It is not possible to use all inputs or outputs in a given installation. Incorrect wiring may result in damage to the equipment.

Connect the terminals of the CGCM unit with copper wire rated at no less than 600V. General purpose wire rated for a minimum temperature of 105 °C (221 °F) may be used.

All wire must be copper. Select circuit wires according to good design practice.

The wire gauge ranges listed in the terminal block label instruction table indicate the physical capabilities of the connector.

Terminals for CGCM devices are located on the front, bottom, and right side panels of the device.

The nine-pin connector on the bottom of the unit is used for communication between CGCM devices in a redundant system. The recommended torque for the terminal screws is 1 N-m (9 lb-in).

Terminals that are used as shield wire landings are found on multiple terminal strips. Shielded terminals with the same name are connected together internally, but are not connected to a protective ground or any internal device circuit.

Excitation power supply

The excitation power supply is connected to the PMG terminals whether it is connected to the generator output (parallel excitation) or to the PMG.

The shunt excitation input is connected to the voltage transformer (VT).

The PMG inputs are located on TB1 and are labelled PMG A, PMG B and PMG C, indicating the respective phase relationship.

The single-phase excitation power supply must be connected to terminals PMG A and PMG C. The PMG inputs require twisted pair connections.

A twisted pair shielded cable is required for the PMG input.

See wiring diagram below.

Chassis Ground

The terminal marked CH GND on TB4 is the chassis ground terminal. There is also a grounding screw on the underside of the mounting flange that connects internally to the CH GND terminal.

Connect the chassis ground to the lower stud on either side of the unit with a minimum 2.6 mm2 (10 AWG) copper wire.

Connect the chassis ground to the lower stud on either side of the unit with a minimum 2.6 mm2 (10 AWG) copper wire and to the CH GND terminal with a 1.6 mm2 (14 AWG) copper wire.

When installed in a system with other CGCM devices, use a separate wire from each device to connect to the ground bus.

Analogue Inputs

The CGCM unit provides a number of analogue inputs for regulating and controlling independent or parallel generator systems. Each input is summarised below.

Generator Voltage Sense Input

The CGCM unit senses generator voltage through a voltage transformer (VT) mounted on the generator output leads.

The CGCM unit uses the voltage measured through the generator voltage sensing input for the generator voltage,

VAR and/or power factor regulation, kW and kVAR load sharing, synchronisation, metering and protection.

The input accepts signals with up to 40% total harmonic distortion (THD) and can be connected for single-phase and three-phase applications.

The generator voltage input is internally scaled by the CGCM unit according to its transformer configuration settings.

The generator voltage sense inputs are labelled V Gen A, V Gen B, V Gen C and V Gen N.

Bus Voltage Detect Inputs

The voltage measured via the bus voltage detection input is used to synchronise the generator with the bus.The CGCM device detects the bus voltage via VT.

Depending on the number of busbars and the type of synchronisation required, there are one or two sets of bus sensing transformers.

If dual bus synchronisation is required, the configuration of the sensing transformers is limited to single phase. In a single breaker system, the inputs are connected in either a single-phase or three-phase configuration.

The inputs can accept signals with up to 40% total harmonic distortion (THD). The bus voltage inputs are internally scaled by the CGCM unit according to its transformer configuration settings.

The busbar voltage detection inputs are labelled