Generac Power Systems 14 kW LP Description and components Part, Terminal Strip / Interconnection

Section 4.1

Description and components

Part 4

DC control

General

This section will familiarize the reader with the various components that make up the DC control system.

Major DC control system components that will be covered include the following:

•A Terminal Strip / Interconnection Terminal

•A Circuit Board.

•An AUTO-OFF-MANUAL Switch.

•A 7.5 Amp Fuse.

Terminal Strip / Interconnection

Terminal

The terminals of this terminal strip are connected to identically numbered terminals on a transfer switch terminal board. The terminal board connects the transfer switch to the circuit board.

The terminal board provides the following connection points:

A.Utility 1 and Utility 2

1.Connect to identically marked terminals on a transfer switch terminal board.

B.23 and 15B

1.Connect to identically numbered terminals on the terminal board of the transfer switch.

2.This circuit connects the circuit board to the transfer relay coil in the transfer switch.

		5B1 23
	0
N1 N2

TERMINAL STRIP

Figure 1. Terminal Strip

Circuit Board

The circuit board controls all standby electric system operations including (a) engine startup, (b) engine running, (c) automatic transfer, (d) automatic retrans- fer, and (e) engine shutdown. In addition, the circuit board performs the following functions:

•Delivers “field boost” current to the generator rotor windings (see “Field Boost Circuit” in Section 2.2).

•Starts and “exercises” the generator once every seven days.

•Provides automatic engine shutdown in the event of low oil pressure, high oil temperature, overspeed, no RPM sense, overcrank, or low battery.

An 18-pin and a 4-pin connector are used to inter- connect the circuit board with the various circuits of the DC systems. Connector pin numbers, associated wires and circuit functions are listed in the CHART on the next page.

If the Utility sensing voltage drops below a preset value, circuit board action will initiate automatic generator startup and transfer to the “Standby” source side.

The crank relay and fuel solenoid valve are energized by circuit board action at the same time.

Digital Input/Output Functions:

Postion	Digital Inputs	Digital Outputs
1	Low Oil Pressure	Not Used
2	High Temperature	Not Used
3	Internal Use	Not Used
4	Internal Use	Not Used
5	Internal Use	Fuel
6	Not Used	Starter
7	Auto	Ignition
8	Manual	Transfer

*DANGER: THE GENERATOR ENGINE WILL CRANK AND START WHEN THE 7-DAY EXERCISER SWITCH IS ACTUATED. THE UNIT WILL ALSO CRANK AND START EVERY 7 DAYS THEREAFTER, ON THE DAY AND AT THE TIME OF DAY THE SWITCH WAS ACTUATED.

Auto-Off-Manual Switch

This 3-position switch permits the operator to (a) select fully automatic operation, (b) start the generator manually, or (c) stop the engine and prevent automatic startup. Switch terminals are shown pictorially and schematically in Figure 6, below.

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