Carrier 30RAP010-060 Part, Number, SUB-MODE Keypad Entry Display Item Expansion Comments

Table 22 — Dual Chiller Configuration (Master Chiller Example) (cont)

SUB-MODE	ITEM	KEYPAD ENTRY		DISPLAY	ITEM EXPANSION	COMMENTS
	LLBL			2	LEAD/LAG BALANCE SELECT	CHANGE ACCEPTED
			ENTER
				LLBL
			ESCAPE
				LLBD	LEAD/LAG BALANCE DELTA
	LLBD			168	LEAD/LAG BALANCE DELTA	DEFAULT 168
			ENTER
				LLBD
			ESCAPE
				LLDY	LAG START DELAY
RSET
	LLDY			5		SCROLLING STOPS
			ENTER
				5		VALUE FLASHES
			ENTER
				10		SELECT 10
	LLDY			10	LAG START DELAY	CHANGE ACCEPTED
			ENTER
				LLDY
			ESCAPE
				RSET
			ESCAPE
	PARA			YES		MASTER COMPLETE
			ENTER

NOTES:

1.Master Control Method (CTRL) can be configured as 0-Switch, 2-Occupancy or 3-CCN.

2.Parallel Configuration (PARA) cannot be changed.

Dual chiller start/stop control is determined by configura- tion of Control Method (Configuration→OPT1→CTRL) of the Master chiller. The Slave chiller should always be config- ured for CTRL=0 (Switch). If the chillers are to be controlled by Remote Contacts, both Master and Slave chillers should be enabled together. Two separate relays or one relay with two sets of contacts may control the chillers. The Enable/Off/ Remote Contact switch should be in the Remote Contact position on both the Master and Slave chillers. The Enable/Off/ Remote Contact switch should be in the Enable position for CTRL=2 (Occupancy) or CTRL=3 (CCN Control).

Both chillers will stop if the Master chiller Enable/Off/ Remote Contact switch is in the Off position. If the Emergency Stop switch is turned off or an alarm is generated on the Master chiller the Slave chiller will operate in a Stand-Alone mode. If the Emergency Stop switch is turned off or an alarm is generated on the Slave chiller the Master chiller will operate in a Stand-Alone mode.

The master chiller controls the slave chiller by changing its Control Mode (Run Status→VIEW→STAT) and its operat- ing setpoint or Control Point (Run Status→VIEW→CT.PT).

THERMISTOR

WIRING*

RETURN	MASTER	LEAVING
FLUID	CHILLER	FLUID

SLAVE

CHILLER

INSTALL DUAL CHILLER LWT

LEAVING FLUID TEMPERATURE

THERMISTOR (T10) HERE

*Depending on piping sizes, use either:

•HH79NZ014 sensor/10HB50106801 well (3-in. sensor/well)

•HH79NZ029 sensor/10HB50106802 well (4-in. sensor/well)

Fig. 16 — Dual Chiller Thermistor Location

	PART				DIMENSIONS in. (mm)
	NUMBER					A		B
10HB50106801				3.10 (78.7)				1.55 (39.4)
10HB50106802				4.10 (104.1)				1.28 (32.5)
		A						0.505/0.495
			B						0.61
									DIA
							6” MINIMUM
	1/4 N.P.T.						CLEARANCE FOR
							THERMISTOR
							REMOVAL

Fig. 17 — Dual Leaving Water Thermistor Well

Temperature Reset — The control system is capable of handling leaving-fluid temperature reset based on return cooler fluid temperature. Because the change in temperature through the cooler is a measure of the building load, the return tempera- ture reset is in effect an average building load reset method. The control system is also capable of temperature reset based on outdoor-air temperature (OAT), space temperature (SPT), or from an externally powered 4 to 20 mA signal. Accessory sen- sors must be used for SPT reset (33ZCT55SPT). The energy management module (EMM) must be used for temperature reset using a 4 to 20 mA signal. See Tables 24 and 25.

38