Carrier ASPAS1CCA007 owner manual Automatic Transfer Operation, Sequence of Automatic Operation

Section 2 — Operation

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

2.3AUTOMATIC 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 connected to the utility power source (Figure 2.2).

2.Be sure that normal UTILITY power source voltage 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 2.4, “Sequence of Automatic Operation.”

‹2.3.1 12 VDC ACCESSORY OUTLET

Your generator is equipped with a 12 VDC accessory outlet in the Generator Control Panel. (Figure 2.1) 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 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

!generator's starting battery and extended use of this outlet may drain the battery and the engine may not start. This outlet should NOT be used for battery charging.

‹2.3.2 120 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 1.1 and 1.2, page 5) 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).

2.4SEQUENCE OF AUTOMATIC

OPERATION

The generator’s control panel houses a control logic circuit board. This board constantly monitors utility 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 activate and connect load circuits to the standby power supply (load terminal lugs T1/T2 connect to terminal lugs E1/E2).

Upon restoration of utility power supply, generator circuit board action signals the transfer switch to transfer loads back to the utility 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.

•If utility source voltage drops below about 70 percent of the nominal supply voltage, the sensor energizes a 15-second timer.

•Once the timer has expired, the engine will crank and start.

B.Engine Warm-up Time Delay

•This mechanism lets the engine warm up for about 10 seconds before the load is transferred to the standby source.

C.Standby Voltage Sensor

•This sensor monitors generator AC output voltage. When the voltage has reached 50 percent of the nominal rated voltage, transfer to standby can occur.

D.Utility Voltage Pickup Sensor

•This sensor monitors utility power supply voltage. When that voltage is restored above 70 percent of the nominal source voltage, a retransfer time delay starts timing.

E.Retransfer Time Delay

•This timer runs for about 15 seconds.

•At end of a 15-second delay, circuit board action de- energizes transfer relay in the transfer switch.

•Retransfer to utility power source then occurs.

F.Engine Cool-down Timer

•When the load is transferred back to utility power source, the engine cool-down timer starts timing.

•The timer will run for about one minute, and the generator will then shut down.

10 Carrier