Friedrich SM21J30A4, Руководство по обслуживанию

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39
HEATING ELEMENT (See Figure 39)
All heat pumps and electric heat models are equipped with a
heating element with the exception of the YS09J10. The "YS",
"ES" and "EK12" models are equipped with a 3.3 KW element.
The "YM", "EM" and "EK18" models are equipped with a 4.0
KW element. The "YL" and "EL" models are equipped with a
5.2 KW element.
The heating element contains a fuse link and a heater limit
switch. The fuse link is in series with the power supply and
will open and interrupt the power when the temperature
reaches 161.6°F, or a short circuit occurs in the heating
element. Once the fuse link separates, a new fuse link must
be installed.
NOTE: Always replace with the exact
replacement.
The heater element has a high limit control. This control is a
bimetal thermostat mounted in the top of the heating element.
HEATING ELEMENT
Should the fan motor fail or filter become clogged, the high
limit control will open and interrupt power to the heater before
reaching an unsafe temperature condition.
The control is designed to open at 110°F ±6°F. Test continuity
below 110°F and for open above 110°F.
The heating element for the "Y" model is energized by an
outdoor thermostat. The outdoor thermostat is adjusted at a
predetermined temperature to bring on the heating element
and turn off the compressor. The room thermostat will then
control the cycling of the element when the selected indoor
temperature is reached.
Testing of the elements can be made with an ohmmeter across
the terminals after the connecting wires have been removed.
A cold resistance reading of approximately 14.5 ohms for the
3.3 KW heater, 11.9 ohms for the 4.0 KW heater and 9.15
ohms for the 5.2 KW heater should be registered.
Figure 39
SEALED REFRIGERATION SYSTEM REPAIRS
IMPORTANT
ANY SEALED SYSTEM REPAIRS TO HEAT PUMP
MODELS REQUIRES THE INSTALLATION OF A
SUCTION LINE DRIER IN THE SUCTION LINE
BETWEEN THE EVAPORATOR AND THE REVERSING
VALVE.
EQUIPMENT REQUIRED
1. Voltmeter
2. Ammeter
3. Ohmmeter
4. E.P.A. Approved Refrigerant Recovery System.
5. Vacuum Pump (capable of 200 microns or less vacuum.)
6. Acetylene Welder
7. Electronic Halogen Leak Detector (G.E. Type H-6 or
equivalent.)
8. Accurate refrigerant charge measuring device such as:
a. Balance Scales - 1/2 oz. accuracy
b. Charging Board - 1/2 oz. accuracy
9. High Pressure Gauge - (0 - 400 lbs.)
10. Low Pressure Gauge - (30 - 150 lbs.)
11. Vacuum Gauge - (0 - 1000 microns)
EQUIPMENT MUST BE CAPABLE OF:
1. Recovery CFC's as low as 5%.
2. Evacuation from both the high side and low side of the
system simultaneously.
3. Introducing refrigerant charge into high side of the sys-
tem.
4. Accurately weighing the refrigerant charge actually in-
troduced into the system.
5. Facilities for flowing nitrogen through refrigeration tub-
ing during all brazing processes.