General Information
8
WSHP-SVX01L-EN
Tracer ZN524 Controls (option)
The digital ZN524 controller is designed to support the ½–
25 ton water-source heat pumps in either a standalone,
peer-to-peer with a Tracer Loop Controller, or as a full
building automation (open protocol) system.
For installation, operation and diagnostics of
aforementioned options see the ZN510 and ZN524 WSHP-
IOP-2 (ZN510) and/or WSHP-PRB002-EN (ZN524).
Pump Module (field installed accessory)
The pump module shall consist of either a single or dual 1/
6 HP bronze pump and a brass 3-way shut-off valve. Cast
iron pumps are also acceptable. The pump module kits
shall contain the necessary components for the
installation, operation and maintenance of the water
circuit of a closed-loop distributed pumping application.
Waterside Economizer (Option)
Instructions for mechanical connection of the waterside
economizer to the water-source heat pump may be found
in the dimensional section of this manual.
The waterside economizer is designed to begin
economizing mode when water temperatures fall below
the field adjustable temperature of 25, 35, 45, 55 or 65°F
(for the Deluxe control option), or below the programmed
set-point (for the ZN524 control option).
When the temperature is less than the setpoint, fluid will
flow into the economizing coil, while simultaneously
halting mechanical operation of the compressor.
Mechanical cooling will continue on a call for a second
stage from the thermostat or system control. Entering
water temperature sensor is factory provided for field
installation on the entering water side of the coil.
Boilerless Control/Electric Heat (Option)
Systems that do not contain a boiler may contain a
boilerless control with electric heat. Trane offers both a
factory mounted electric heat option, and a field mounted
duct heater option.
If the ½–5 ton GEH, GEV and EXH/V070 unit incorporates
the factory mounted option, the unit will ship from the
factory with an internally mounted nichrome open wire
heating element, designed to start-up electric heat as the
systems primary heat in the event entering water
temperature falls below 55°F. Once the entering water
temperature rises above 60°F, the boilerless controller
returns the unit to normal compressor heating operation,
and locks out the electric heater.
For units comprised of the field installed duct heater
option, the unit will ship from the factory with controls
available to interface with the field provided electric heat
selection.
Note:
For geothermal applications, the boilerless
controller has an adjustable setting of 25, 35, 45, 55,
and 60 degrees.
Supplemental or Boilerless Electric Heat
(option)
The GEH/V 6-25 ton models which contain boilerless
control electric heat or supplemental electric heat will
contain the controls interface ONLY for field provided
electric heat selection. The heater for this model shall be
external to the equipment by the contractor for ease of
installation. All power connections for the electric heater
will be completely separate from the unit for field supplied
electric heat.
Note:
When the unit has boilerless control, the electric
heat is not used as supplemental electric heat, but
as a primary heat.
Hot Gas Reheat (option)
With the reheat option, the return-air from the space is
conditioned by the air-to-refrigerant coil, then reheated by
the reheat coil to control not only the space temperature,
but to also reduce the relative humidity of the space. When
operating in the reheat mode (meaning the sensible
temperature has been met in the space), the humidistat
signals the reheat relay coil to energize, allowing the high
pressure refrigerant gas to flow from the compressor
through the reheat valve, into the reversing valve, or
reheat coil.
A switching relay has been provided for the reheat
application to adjust the blower motor from normal
operation to low speed when the hot gas reheat is
energized (for ½–5 ton and EXH/V070 equipment only).
Note:
A high static blower motor is required to support
the hot gas reheat option for the GEH/V ½–5 ton.
Note:
Units containing the hot gas reheat option should
not be used as a make-up air unit.
Summary of Contents for Axiom EXH018
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