Carrier 30GN040-420 Accessory Unloader Installation, Ð Sensor Bus Wiring Communications

Fig. 19 Ð Sensor Bus Wiring

(Communications)

PROCESSOR MODULE (PSIO) (Fig. 20)

Inputs Ð Each input channel has 3 terminals; only 2 of the terminals are used. Application of machine determines which terminals are used. Always refer to individual unit wiring for terminal numbers.

Outputs Ð Output is 24 vdc. There are 3 terminals, only 2 of which are used, depending on application. Refer to unit wiring diagram.

NOTE: Address switches (see Fig. 20) must be set at 01 (dif- ferent when CCN connected).

LOW VOLTAGE RELAY MODULE (DSIO-LV) (Fig. 21)

Inputs Ð Inputs on strip J3 are discrete inputs (ON/OFF). When 24-vac power is applied across the 2 terminals in a channel it reads as on signal. Zero v reads as an off signal.

Outputs Ð Terminal strips J4 and J5 are internal relays whose coils are powered-up and powered-off by a signal from microprocessor. The relays switch the circuit to which they are connected. No power is supplied to these connections by DSIO module.

4 IN/4 OUT MODULE (SIO) (Fig. 22) Ð 4 In/4 Out mod- ule allows the following features to be utilized:

1.Temperature Reset by outdoor air or space temperature. A remote thermistor (Part No. 30GB660002) is also re- quired.

NOTE: This accessory is not required for return water temperature reset.

2.Temperature Reset by remote 4 to 20 mA signal.

3.Demand Limit by remote 2-stage switch.

4.Demand Limit by remote 4 to 20 mA signal

5.Dual Set Point by remote switch.

The options module is standard. Remember to recon®g- ure the chiller for each feature selected (see Table 14). For temperature reset, demand limit, and dual set point, desired set points must be entered through keypad and display mod- ule (see Set Point Function section on page 38).

See Table 19 for overall troubleshooting information.

ACCESSORY UNLOADER INSTALLATION

Some of the 30G Flotronic™ II units come standard with unloader(s), and many permit additional unloader(s) to be added if desired. See Table 20.

IMPORTANT: The following combinations ARE NOT permitted (combinations are per circuit):

1.Two unloaders and hot gas bypass

2.Four compressors and 2 unloaders.

3.Four compressors, 1 unloader, and hot gas bypass.

PWR Ð Power

Fig. 20 Ð Processor Module (PSIO)

		LEGEND
COMM	Ð	Communications Bus	NO Ð Normally Open
NC	Ð	Normally Closed	PWR Ð Power

Fig. 21 Ð Low-Voltage Relay Module (DSIO)

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