ICP CHS180, Installation, Start-Up And Service Instructions Manual

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Split System Heat Pumps Installation Instructions
13
Pre--Start--Up
Do not attempt to start the condensing unit, even
momentarily, until the following steps have been
completed. Compressor damage may result.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in shorten life
of unit components.
System Check
1. Check all air handler(s) and other equipment
auxiliary components. Consult the manufacturer’s
instructions regarding any other equipment
connected to the condensing unit. If unit has
field--installed accessories, be sure all are properly
installed and correctly wired. If used, airflow switch
must be properly installed.
2. Backseat (open) compressor suction and discharge
valves. Now close valves one turn to allow refrigerant
pressure to reach test gages.
3. Open liquid line service valve.
4. Check tightness of all electrical connections.
5. Be sure unit is properly leak checked, dehydrated,
and charged.
6. Electrical power source must agree with nameplate
rating.
7. Crankcase heater must be firmly locked into
compressor crankcase. Be sure crankcase is warm
(heater must be on for 24 hours before starting
compressor).
Start--Up
Compressor crankcase heater must be on for 24 hours
before start--up. After the heater has been on for 24 hours,
the unit can be started.
COMPRESSOR OVERLOAD -- This overload interrupts
power to the compressor when either the current or internal
motor winding temperature becomes excessive, and
automatically resets when the internal temperature drops
to a safe level.
This overload may require up to 60 minutes (or longer) to
reset. If the internal overload is suspected of being open,
disconnect the electrical power to the unit and check the
circuit through the overload with an ohmmeter or continuity
tester.
START UNIT -- The field disconnect is closed, the fan
circuit breaker is closed, and the space thermostat is set
above ambient so that there is no demand for cooling. Only
the crankcase heater will be energized.
Next, close the compressor circuit breaker and then reset
space thermostat below ambient so that a call for cooling is
ensured.
NOTE: Do not use circuit breaker to start and stop the
compressor except in an emergency.
After starting, there is a delay of at least 3 seconds before
compressor starts.
Refrigerant Charge
Add charge amount as required for the total system, See
Figure 7 and Table 4. Do not exceed maximum refrigerant
charge. Vary refrigerant until the conditions of the chart are
met. Note that charging charts are different from type
normally used. Charts are based on charging the units to
the correct subcooling for the various operating conditions.
Accurate pressure gage and temperature sensing device
are required.
Connect the pressure gage to the service port on the liquid
line service valve. Mount the temperature sensing device
on the liquid line, close to the liquid line service valve and
insulate it so that outdoor ambient temperature does not
affect the reading. Indoor airflow must be within the normal
operating range of the unit. Operate unit a minimum of 15
minutes. Ensure pressure and temperature readings have
stabilized. Plot liquid pressure and temperature on chart
and add or reduce charge to meet curve. Adjust charge to
conform with charging chart, Figure 7, using the liquid
pressure and temperature to read chart.
If the sight glass is cloudy, check refrigerant charge again.
Ensure all fans are operating. Also ensure maximum
allowable liquid lift has not been exceeded. If charged per
chart and if the sight glass is still cloudy, check for a
plugged filter drier or a partially closed solenoid valve.
Replace or repair, as needed.
Unit must be charged in the Cooling Mode only.
N
Fig. 7 CHS180 CHARGING CHART