Generac 005030-0 (15kW) owner manual Generator AC Neutral Connections, Connection Diagram ATS Mode

Section 2 — Installation

Liquid-cooled 15, 20 and 25 kW Generators

2.8GENERATOR AC NEUTRAL

CONNECTIONS

The manufacturer uses an UNGROUNDED AC neu- tral. Grounding is recommended only at the main service entrance. If the neutral wire is grounded and one of the phase loads becomes grounded, the exces- sive current opens the load circuit breaker or col- lapses the generator field. The actual result depends on the electrical characteristics of the particular installed generator.

The HS Type transfer switch is controlled by the gen- erator circuit board via control wires 23 and 194. Wire 23 connects the relay driver output (collector of an NPN transistor) on the generator circuit board to the "low side" (Terminal 23) of the transfer relay coil in the transfer switch. Wire 194 connects positive battery voltage from the generator circuit board to the "high side" (Terminal 194) of the transfer relay coil in the transfer switch.

2.9AUTOMATIC TRANSFER SWITCH

(ATS MODE)

When this generator, along with an HS Type automat- ic transfer switch has been installed and connected, a circuit board in the generator control panel con- stantly monitors the utility voltage and controls the operation of the transfer switch.

To implement this mode of operation, Position 2 of the eight-position DIP switch, which is located on the generator circuit board (see Figure 3.2), must be in the OFF position. In ATS Mode utility voltage sensing, weekly exercising, and load transferring is under the control of the generator.

Should the utility voltage drop below a preset value, and remain at this low voltage for a preset amount of time, the generator cranks and starts. After the gen- erator starts, the transfer switch transfers the load circuits to the generator so the generator can power them. When the utility source voltage has been restored, the transfer switch re-transfers the load cir- cuits back to the utility source voltage and the gener- ator shuts down.

If generator wires 23 and 194 are not wired to

!the correct terminals in the transfer switch, the circuit board in the generator control panel will be damaged.

In order for the generator utility voltage sensing and battery charging functions to work, it is necessary to provide a 5 amp fused 240Vac utility source connec- tion from the transfer switch main N1 and N2 termi- nals to the generator control panel N1 and N2 termi- nals (See Figure 2.3).

Transfer Switch terminals N1 and N2 (also called Utility 1 and Utility 2) are the input utility AC power connections to the Transfer Switch. Transfer Switch terminals T1 and T2 (also called Load 1 and Load 2) are the transfer switch AC output power terminals that go to the load circuit distribution panel. Transfer Switch terminals E1 and E2 are the AC power termi- nals that come from the generator's main alternator.

Figure 2.3 - Connection Diagram (ATS Mode)

		FROM UTILITY
				MAIN LINE
				CIRCUIT
				BREAKER
				OR FUSE
FUSE			N1 N2
	N1			T1
	N2			T2
FUSE

TO LOAD

FEEDER CIRCUITS

LOAD

DISTRIBUTION

PANEL

GENERATOR

	194
HS TYPE	23
TRANSFER
SWITCH
E1 E2

194

23

178

183

E1 E2

N2 N1

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