Carrier 50PEC09-18 specifications Recommended Thermostat Wire Sizes, SPT Sensors

OPTIONAL WALL-MOUNTED THERMOSTAT — The 50PEC water source heat pump units are built with standard in- ternal thermostats in either manual changeover (MCO) or auto- matic changeover (ACO) configuration. Refer to Fig. 17-20.

When desired, the unit can be furnished with a 24-v control circuit which is field wired to a Carrier-supplied accessory re- mote thermostat. Most heat pump thermostats can be used with the controller. Use a thermostat with Y, G, O and W outputs. Refer to unit wiring diagrams in Fig. 21 and 22 and Aquazone Controls, Operation, and Troubleshooting Instructions for addi- tional information.

Vendor installation instructions and additional installation information is shipped with each thermostat.

NOTE: Low-voltage wiring between the unit and the wall ther- mostat must comply with all applicable electrical codes (i.e., NEC and local codes), and be completed before the unit is installed.

Table 3 lists recommended wire sizes and lengths to install the thermostat. The total resistance of low-voltage wiring must not exceed 1 ohm. Any resistance in excess of 1 ohm may cause the control to malfunction because of high voltage drop.

Table 3 — Recommended Thermostat Wire Sizes

WIRE SIZE	MAX WIRE LENGTH*
18-Gage	75 ft
16-Gage	125 ft
14-Gage	200 ft

*Length = Physical distance from thermostat to unit.

OPTIONAL PREMIERLINK™ CONTROLLER — This di- rect digital controller (DDC) allows the water source heat pump to be incorporated into a Carrier Comfort Network® (CCN) system installation. PremierLink control is factory- installed with the Complete C controller, or field-installed with the Deluxe D control option. Refer to Fig. 23 and 24.

WSHP OPEN WIRING — The WSHP Open controller will be factory wired to the Complete C or Deluxe D control board, however, the system wiring will need to be completed utilizing WSHP Open controller wiring diagrams and the Third Party Integration (TPI) Guide. Factory installation includes harness, LWT (leaving water temperature), supply air, and condensate sensor.

WARNING

Disconnect all power to the unit before performing mainte- nance or service. Unit may automatically start if power is not disconnected. Failure to follow this warning could cause personal injury, death, and/or equipment damage.

Wiring Sensors to Inputs — Sensors can be wired to the WSHP Open controller’s inputs. See Table 4.

All field control wiring that connects to the WSHP Open con- troller must be routed through the raceway built into the corner post. The raceway provides the UL required clearance between high and low-voltage wiring.

1.Pass control wires through the hole provided in the corner post.

2.Feed the wires through the raceway to the WSHP Open controller.

3.Connect the wires to the removable Phoenix connectors.

4.Reconnect the connectors to the board.

Field-Supplied Sensor Hardware — The WSHP Open con- troller is configurable with the following field-supplied sen- sors. See Table 4.

Table 4 — Field-Supplied Sensors for

WSHP Open Controller

SENSOR	NOTES
Space Temperature Sensor	Field Installed (Must be used with
(SPT)	WSHP Open controller.)
Outdoor Air	Network Sensor
Temperature Sensor
Indoor Air Quality Sensor	Required only for demand
(Separate Sensor)	control ventilation.
Space Relative Humidity	Separate Sensor
Sensor

NOTE: BACview6 Handheld or Virtual BACview can be used as the user interface.

For specific details about sensors, refer to the literature sup- plied with the sensor.

Wiring a SPT Sensor — A WSHP Open controller is connect- ed to a wall-mounted space temperature (SPT) sensor to moni- tor room temperature using a Molex plug.

The WSHP Open system offers the following SPT sensors. See Table 5.

Table 5 — SPT Sensors

SENSOR	PART	FEATURES
	NUMBER
SPT	SPS	• Local access port
Standard		• No operator control
		• Slide potentiometer to adjust set point
SPT Plus	SPPL	• Manual on button to override schedule
		• LED to show occupied status
		• Local access port
		• LCD display
		• Manual on button to override schedule
		• Warmer and cooler buttons to adjust set
SPT Pro	SPP	point
		• Info button to cycle through zone and
		outside air temperatures, set points, and
		local override time
		• Local access port
		• LCD display
		• Manual on button to override schedule
		• Warmer and cooler buttons to adjust set
SPT Pro		point
	SPPF	• Info button to cycle through zone and
Plus
		outside air temperatures, set points, and
		local override time
		• Local access port
		• Fan speed*

*The SPT Pro Plus fan speed adjustment has no effect in this application.

Wire SPT sensors to the WSHP Open controller’s Rnet port. An Rnetbus can consist of any of the following combinations of devices wired in a daisy-chain configuration:

•1 SPT Plus, SPT Pro, or SPT Pro Plus sensor

•1 to 4 SPT Standard sensors

•1 to 4 SPT Standard sensors and 1 SPT Plus, SPT Pro, or SPT Pro Plus sensor

•Any of the above combinations, plus up to 2 BACview6 Handheld but no more than 6 total devices

NOTE: If the Rnetbus has multiple SPT Standard sensors, each sensor must be given a unique address on the Rnetbus. See the Carrier Open Sensor Installation Guide.

Use the specified type of wire and cable for maximum signal integrity. See Table 6.

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