Carrier 30XA080-500 specifications Thermal Flow Sensor, A30-3432

DV

Heater (Optional)

LEGEND a30-4416

D— Drain, 3/4-in. NPT FS — Flow Switch

PP	— Pipe Plug, 1/4-in. NPT		20
T1	—	Leaving Water Thermistor	20MeshshStrainer
T2	—	Entering Water Thermistor
V	— Vent, 1/4-in. NPT

T1	PP
	Chilled Water Out
		Chilled Water In
FS	PP	T2

Fig. 28 — Typical Piping Diagram on 30XA Units without Hydronic Package

IMPORTANT: Automatic vents should be located in accessible locations for maintenance purposes and protected from freezing.

COOLER PUMP CONTROL — It is required that cooler pump control be utilized on all chillers unless the chilled water pump runs continuously or the chilled water system contains a suitable antifreeze solution. Control of dual external pumps re- quires installation of the external pump control accessory pack- age (Part No. 00EFN900003200A).

WARNING

Applications that utilize fresh water as the circulated fluid require that the circulating pump be controlled directly by the chiller. Operation with fresh water is not fail-safe should there be a loss of power to the chiller or to the circu- lating pump. Freeze damage due to power loss or disabling chiller pump control in fresh water systems will impair or otherwise negatively affect the warranty.

If cooler pump control is not utilized, it is required that the chiller be electrically interlocked with the chilled water pump starter. The interlock should be wired to terminals TB5-1 and TB5-2. It is also required that the cooler pump output be used as an override to the chilled water pump control circuit to pro- vide additional freeze protection.

Refer the control and power wiring schematic on page 63 for proper connection of the cooler pump output. The cooler pump output will remain energized for 30 seconds after all compressors stop due to an OFF command. In the event a freeze protection alarm is generated, the cooler pump output will be energized regardless of the cooler pump control soft- ware configuration. The cooler pump output is also energized anytime a compressor is started and when certain alarms are generated. A thermal flow sensor is factory installed in the en- tering fluid nozzle to prevent operation without flow through the cooler. See Fig. 29. The flow sensor is factory wired.

Proper software configuration of the cooler pump control parameters is required to prevent possible cooler freeze-up. Refer to the Controls, Start-Up, Operation, Service and Troubleshooting guide for more information.

BRINE UNITS — Special factory modifications to the units are required to allow them to operate at fluid temperatures less than 40 F (4.4 C). Be sure that the fluid has sufficient

inhibited glycol or other suitable corrosion-resistant anti- freeze solution to prevent cooler freeze-up.

PREPARATION FOR YEAR-ROUND OPERATION — In areas where the piping or unit is exposed to 32 F (0° C) or lower ambient temperatures, freeze-up protection is required using inhibited glycol or other suitable corrosion-resistant anti- freeze solution and electric heater tapes. Heater tapes on piping should have a rating for area ambient temperatures and be cov- ered with a suitable thickness of closed-cell insulation. Route power for the heater tapes from a separately fused disconnect. Mount the disconnect within sight from the unit per local or NEC (National Electric Code) codes. Identify disconnect at heater tape power source with a warning that power must not be turned off except when servicing unit.

IMPORTANT: Adding antifreeze solution is the only certain means of protecting the unit from freeze-up if heater fails or electrical power is interrupted or lost while temperatures are below 32 F (0° C).

A drain connection is located at the bottom of the cooler head. See Fig. 2-14 for connection location. Install shut-off valves to the drain line before filling the system with fluid.

a30-3432

Fig. 29 — Thermal Flow Sensor

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