Generac Power Systems 04389-3, 04456-3, 04390-3 owner manual Automatic Transfer Operation

Section 3 — Operation

Air-cooled 7 kW, 12 kW and 15 kW Generators

‹3.2.2 “OFF” POSITION

This switch position shuts down the engine. This position also prevents automatic operation.

Figure 3.1 – Generator Control Panel

‹3.3.1 12 VDC ACCESSORY OUTLET

Your generator is equipped with a 12 VDC accessory outlet in the Generator Control Panel. (Figure 3.1) With the generator running or in standby mode, this outlet may be used to temporarily power low power accessories such as a work light, cell phone, radio or any other automotive style accessory. This outlet is

OUTLET FUSE		EXTERNAL
		GFCI
7.5A		CIRCUIT
	MAN.	BREAKER
AUTO OFF
		12 VDC
SYST
SET
EXERCISE	ACCESSORY
TIME	OUTLET 7.5A MAX

SYSTEM SET

LOW OIL

HIGH TEMP.

OVER SPEED

OVER CRANK

F L A S H I		N L E D =
N O		S E N S E
4 F L S H	R E	L E D S =
E X E R	R N O T S E T

capable of delivering a MAXIMUM of 7.5 Amps. If the accessory to be used through this circuit demands too much power, the fuse that protects this circuit will melt open and the circuit will not be functional.

This 12 VDC outlet draws power from the gen-

erator's starting battery and extended use of

this outlet may drain the battery and the

engine may not start. This outlet should NOT be

‹3.2.3 “MANUAL” POSITION

Set the switch to MANUAL to crank and start the engine. Transfer to standby power will not occur unless there is a utility failure.

With the switch set to AUTO, the engine may crank and start at any time without warning. Such automatic starting normally occurs when utility power source voltage drops below a pre- set level or during the normal exercise cycle. To prevent possible injury that might be caused by such sudden starts, always set the switch to OFF and remove the fuses before working on or around the generator or transfer switch. Then, place a “DO NOT OPERATE” tag on the genera- tor panel and on the transfer switch.

3.3AUTOMATIC TRANSFER

OPERATION

To select automatic operation, do the following:

1.Make sure the transfer switch main contacts are set to their UTILITY position, i.e., loads con- nected to the utility power source (Figure 3.2).

2.Be sure that normal UTILITY power source volt- age is available to transfer switch terminal lugs N1 and N2.

3.Set the generator’s AUTO/OFF/MANUAL switch to AUTO.

4.Set the generator’s main circuit breaker to its ON (or closed) position.

With the preceding steps complete, the generator will start automatically when utility source voltage drops below a preset level. After the unit starts, loads are transferred to the standby power source. Refer to Section 3.4, “Sequence of Automatic Operation.”

used for battery charging.

‹ 3.3.2 120 VAC GFCI OUTLET

Your generator is equipped with an external, 15 amp, 120 volt, GFCI convenience outlet that is located in the right rear of the generator enclosure. (Figures

1.1and 1.2) When the generator is running, in the absence of utility power, this outlet may be used to power items outside your home such as lights or power tools. This outlet may also be used when utility power is present by running the generator in manual mode. This oultlet does not provide power if the generator is not running. This outlet is protected by a 15-amp circuit breaker located in the generator control panel. (Figure 3.1).

3.4SEQUENCE OF AUTOMATIC

OPERATION

The generator’s control panel houses a control logic circuit board. This board constantly monitors util- ity power source voltage. Should that voltage drop below a preset level, circuit board action will signal the engine to crank and start. After the engine starts, the circuit board signals the transfer switch to acti- vate and connect load circuits to the standby power supply (load terminal lugs T1/T2 connect to terminal lugs E1/E2).

Upon restoration of utility source voltage above a preset level, generator circuit board action signals the transfer switch to transfer loads back to that power supply. After retransfer, the engine is signalled to shut down.

The actual sequence of operation is controlled by sensors and timers on a control logic circuit board, as follows:

A.Utility Voltage Dropout Sensor

• This sensor monitors utility source voltage.

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