Trane WSHP-DS-6 manual Features, Benefits, Volt Controls, Safety Devices, Low Pressure Switch

Models: WSHP-DS-6

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24 Volt Controls

24 Volt Controls

All electrical controls and safety de- vices are factory wired, tested, and mounted in the unit. The control package includes:

θCompressor contactor

θ24 Volt transformer

θLockout relay

θCompressor run capacitor (1- phase units only)

θReversing valve coil (For heat pump only)

θFuse (for desuperheater)

A terminal strip with 1/4” fork con- nections will be provided for field thermostat control wiring. (See Fig- ure 3).

Safety Devices

Each Trane water-to-water unit con- tains safety devices to prevent com- pressor damage. These include:

Features

Controls

and

 

Benefits

 

Lockout

50 VA Transformer

24 VAC Contactor

Relay

 

Ground

Compressor

Run Capacitor

Safety DevicesLow Voltage

High Voltage

2 Amp Fuse

(for use with 10 Pole Terminal

desuperheater Strip option)

Low Voltage

Thermostat

 

Figure 3: Controls

θLow pressure switch

θHigh pressure switch

θTemperature sensor (freezestat)

θInternal overload protection

Low Pressure Switch

The low pressure switch prevents compressor operation under low charge or in excessive loss of charge situations. This device is set to activate at refrigerant pressures of 35 psig when a 35 F low temper- ature detection thermostat is ap- plied. An optional 7 psig pressure switch is available when using a 20

Ftemperature low temperature de- tection thermostat.

High Pressure Switch

Low Temperature Detection Thermostat

The low water temperature detec- tion thermostat is provided to pro- tect the water-to-refrigerant heat exchanger from freezing. This de- vice prevents compressor opera- tion if leaving water temperature is below 35 F. An optional 20 F tem- perature thermostat may be applied for low water temperatures where an appropriate antifreeze solution is used.

Lockout Relay

When the safety controls are acti- vated to prevent compressor short cycling, the lockout relay (circuit) can be reset at the thermostat, or by cycling power to the unit.

Thermostat Hook-up

Low voltage and high voltage knockouts are provided in the top half of the unit. All control wiring to the unit should be 24 Volt.

(See Figure 4 for termination points).

For internal overload protection, Trane provides a high pressure switch. This de-energizes the com- pressor when discharge pressure become excessive.

24V Power

Compressor Reversing Valve

(energized in clg)

Figure 4: Typical thermostat termination points

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Trane WSHP-DS-6 manual Features, Benefits, Volt Controls, Safety Devices, Low Pressure Switch, High Pressure Switch