Trane GSWD, EXWA, WPWD manual General Information

General Information

Unit Nameplate

The unit nameplate is located at the front of the unit. It includes the unit model number, serial number, electri- cal characteristics, refrigerant charge, and other pertinent unit data.

Compressor Nameplate

The nameplate for the compressors are located on the compressor shell.

Unit Description

Before shipment, each unit is leak test- ed, dehydrated, charged with refriger- ant and run tested for proper control operation.

Water-to-Refrigerant Coils

The brazed-plate water-to-refrigerant heat exchangers for the 2-ton through 6-ton equipment are constructed of stainless steel.

The water-to-refrigerant heat ex- changers for the 20-ton equipment are an inner copper tube or cupro-nickel (option available on the source-side only) and steel tube (tube-within-a- tube) design.

Both heat exchanger types are leak tested to assure there is no cross leak- age between the water and refrigerant gas.

Water Connections

One inch brass swivel connections are provided for the 2-ton through 6-ton equipment. Each brass fitting has a one inch gasket for the connector. The gaskets are shipped in the electrical compartment to prevent loss at the job site.

Water connections for the 20-ton are located inside the unit at the units front (source-side) and back (load- side). The fitting consist of a 2-inch fe- male pipe threaded connection.

Controls

The control system offered to control the unit is a Basic 24 volt control for the 2-ton through 6-ton unit sizes, and a deluxe 24 volt micro processing board for the 20-ton unit.

All power wiring to the equipment is made at the unit contactor for the 2-

ton through 6-ton equipment, and at the power block for the 20-ton equip- ment.

All low voltage wiring is made at the unit’s low voltage terminal board.

Wiring Connections

Troubleshooting and connection dia- grams for the equipment may be locat- ed in the back of this manual.

Basic 24V Controls

(for 2-ton through 6-ton units)

Safety devices for equipment contain- ing the basic 24V control option in- clude a low pressure switch and a freezestat to prevent compressor op- eration during low temperature activi- ty. The switch is set to activate at refrigerant pressures of 35 psig or 7 psig to fit most applications.

A high pressure switch prevents com- pressor operation during high or ex- cessive discharge pressures exceeding 395 psig.

The lockout relay communicates the low or high pressure situation to the compressor to prevent operation. The relay may be reset at the thermostat, or by cycling power to the unit.

General alarm may be accomplished through the lockout relay to drive light emitting diodes (LEDs) on a field sup- plied status indicating thermostat. Ter- minal 6 on the lockout relay is open for field use in malfunction indications.

This feature will drive dry contacts only, and cannot be used to drive field installed control inputs.

Deluxe 24V Controls (for 20-ton unit)

Units containing the Deluxe 24V con- trol design will incorporate a micro- processor-based control board. The Trane microprocessor board is factory wired to a terminal strip to provide all necessary terminals for field connec- tion. The deluxe board is equipped with a random start relay, anti-short cycle timer, brown out protection, compressor disable, unit safety con- trol, diagnostics and a generic relay

(which may be available for field use). See page 17 for diagnostic informa- tion.

Desuperheater

(Option for 2-ton through 6-ton units) For units containing the desuperheat- er option, the unit is shipped from the factory with a desuperheater water coil and pump mounted internal to the unit cabinetry. For domestic hot water hook-up instructions, see manual WSHPC-IN-4 or 72-9006-02.

The desuperheater pump fuse is locat- ed in the control box within a contain- er. The fuse is not factory installed to avoid possible pump damage at initial start-up. If the fuse in installed and the unit is started without water in the sys- tem, the pump will be damaged. See page 17 for fuse installation.

Schrader Connections Connections for the low and high side of the refrigeration system are located conveniently on the unit’s right side for the 2-ton through 6-ton units, and behind the front, refrigeration access panel for the 20-ton unit.

WSHP-SVX02A-EN 5