DC CONTROL WIRING — CONTROL BOX BACK PANEL

Control Box

The control box contains the following:

„Digital Control Module

There are several digital control modules available for MQ Power industrial generator sets. Reference your supplied digital control manual for detailed information.

„Control Box Back Panel Components

Figure 31 shows the components found in the Control Box back panel. The actual configuration of these components may vary with each control module model depending on the desired specifications and DC controls used. However. the typical contents are as follows:

zStandard Electronic Governor

zTB1 Terminal Block

zControl Relays

zFuses

The definitions below describe the components of the "Control Box" back panel

1Electronic Governor (Standard) – This electronic speed control exhibits fast and precise response to transient load changes. When used in conjunction with a proportional electric actuator, the governor offers closed loop governing.

Either isochronous or droop governing modes can be selected. The engine's idle speed is variable and selected by a simple switch closure. Engine exhaust smoke during start-up can be minimized when the starting fuel adjustment is optimally set.

2Start Relay (K2) – This relay interfaces

with the engine (75-150kW) and electronic

Figure 31. Typical Inner Control Box Panel

governor controller (if present) for start and

 

stop functions of the generator.

 

3Idle Relay (K4) – This optional relay is installed to interface with the voltage regulator sensing circuits when the optional idle switch is used.

4ShuntTrip Relay (K5) – This relay optional relay is installed to trip the main output circuit breaker under fault conditions. This circuit can be wired to the genset controller to trip the breaker or a shutdown condition.

This relay can also be wired to an external (customer supplied) circuit for external trip control of the breaker.

5Low Coolant Level Relay (K3) – This relay is installed to interface with the low coolant level switch to the genset controller.

6Relay DIN Rail – This rail holds all the relays used for DC controls.

7Terminal Block One (TB1) – This terminal block is used for DC control wiring. See the generator set wire diagram (Figure 34) on page 72 for details.

8Control Power Fuse – This fuse protects terminal block one (TB1) from overcurrent. Remove this fuse when servicing TB1.

PAGE 70 — INDUSTRIAL GENERATOR SETS — APPLICATION & INSTALLATION MANUAL — REV. #4 (09/07/07)

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Multiquip MQP30DZ, MQP20IZ, MQP40IZ DC Control Wiring Control BOX Back Panel, „ Control Box Back Panel Components