Electrical - Low Voltage Wiring - Heat Controller HSS Series Installation, Operation & Maintenance Instructions Manual

H E AT C O N T R O L L E R , I N C . W AT E R - S O U R C E H E AT P U M P S
R e s i d e n t i a l S p l i t - 6 0 H z R 2 2 & R 4 1 0 A
R e v. : 5 J u n e , 2 0 0 8

Electrical - Low Voltage Wiring

Figure 23: FP1 Limit Setting
CXM PCB
Accessory Connections
A terminal paralleling the compressor contactor coil has been
provided on the CXM control. Terminal "A" is designed to
control accessory devices, such as water valves. Note: This
terminal should be used only with 24 Volt signals and not
line voltage. Terminal "A" is energized with the compressor
contactor. See Figure 24 or the specific unit wiring diagram
for details.
Figure 24: Accessory Wiring
Water Solenoid Valves - "Indoor" Compressor
Section Only
An external solenoid valve(s) should be used on ground
water installations to shut off flow to the unit when the
compressor is not operating. A slow closing valve may be
required to help reduce water hammer. Figure 24 shows
typical wiring for a 24VAC external solenoid valve. Figures
25 and 26 illustrate typical slow closing water control valve
wiring for Taco 500 series (HCI P/N AVM...) and Taco ESP
series valves. Slow closing valves take approximately
60 seconds to open (very little water will flow before 45
seconds). Once fully open, an end switch allows the
compressor to be energized. Only relay or triac based
electronic thermostats should be used with slow closing
valves. When wired as shown, the slow closing valve will
operate properly with the following notations:
1. The valve will remain open during a unit lockout.
2. The valve will draw approximately 25-35 VA through the
"Y" signal of the thermostat.
Note: This valve can overheat the anticipator of an
28
JW3-FP1 jumper
should be clipped
for low temperature
operation
H e a t C o n t r o l l e r, I n c . W a t e r - S o u r c e H e a t i n g a n d C o o l i n g S y s t e m s
electromechanical thermostat. Therefore, only relay or triac
based thermostats should be used.
Two-stage HTS Units
Two-stage units should be designed with two parallel valves
for ground water applications to limit water use during first
stage operation. For example, at 1.5 gpm/ton [2.0 l/m per
kW], a model 049 unit requires 6 gpm [23 l/m] for full load
(2nd stage) operation, but only 4 gpm [15 l/m] during 1st
stage operation. Since the unit will operate on first stage
80-90% of the time, significant water savings can be realized
by using two parallel solenoid valves with two flow regulators.
In the example above, stage one solenoid would be installed
with a 4 gpm [15 l/m] flow regulator on the outlet, while stage
two would utilize a 2 gpm [8 l/m] flow regulator. When stage
one is operating, the second solenoid valve will be closed.
When stage two is operating, both valves will be open,
allowing full load flow rate.
Figure 27 illustrates piping for two-stage solenoid valves.
Review figures 24-26 for wiring of stage one valve. Stage two
valve should be wired between "Y2" (compressor solenoid
-- wire nut connection) and terminal "C." NOTE: When EWT
is below 50°F [10°C], a minimum of 2 gpm per ton (2.6 l/m
per kW) is required.
Figure 25: AMV Valve Wiring
2
1
Heater Switch
Thermostat
Figure 26: Taco SBV Valve Wiring
Unidad Empacada
2
1
Calentador Interruptor
Termostato
AMV
3
Taco Valve
AVM
3
Taco Válvula