Carrier GT-GS Indoor Split Series, Инструкция по установке, эксплуатации и обслуживанию, Страница: 31 / 50

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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
C a r r i e r : Tu r n t o t h e E x p e r t s
Figure 23: FP1 Limit Setting
CXM PCB
JW3-FP1 jumper
should be clipped
for low temperature
operation
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 speci
fi c 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
fl ow 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 (Carrier Geothermal P/N AVM…)
and Taco ESP series valves. Slow closing valves take
approximately 60 seconds to open (very little water will
fl ow
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
electromechanical thermostat. Therefore, only relay or triac
based thermostats should be used.
Two-stage Units
Two-stage units should be designed with two parallel valves
for ground water applications to limit water use during
fi rst
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
fi rst stage 80-
90% of the time, signi fi cant water savings can be realized by
using two parallel solenoid valves with two fl ow regulators.
In the example above, stage one solenoid would be installed
with a 4 gpm [15 l/m]
fl ow regulator on the outlet, while stage
two would utilize a 2 gpm [8 l/m] fl ow 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
fl ow rate.
Figure 27 illustrates piping for two-stage solenoid valves.
Review
fi gures 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
C
C
Thermostat
Y1
1
2
3
Y1
AVM
Taco Valve
Heater Switch
Figure 26: Taco SBV Valve Wiring
Electrical - Low Voltage Wiring