Components Testing - Friedrich 000 BTU'S Service Manual

ComPonEntS tEStIng (Continued)
HEATER ELEMENTS AND LIMIT SWITCHES'
SPECIFICATIONS
All heat pumps and electric heat models are equipped
with a heating element and a limit switch (bimetal ther-
mostat). The limit is in series with the element and will
interrupt the power at a designed temperature.
Should the blower motor fail, filter become clogged or air-
flow be restricted etc., the high limit switch will open and
interrupt the power to the heater before reaching an un-
safe temperature condition.
VPAK 9K, 12K and 18K BTUs Models:
2.5 KW, 230 V, Resistance 18.61 Ohms + - 5%.
Has 1 Limit Switch, Opens at 120° F, Closes at 90° F,
It has a One Time Open Temp. of 145° F.
3.4 KW, 230 V, Resistance 13.68 Ohms + - 5%.
Has 1 Limit Switch, Opens at 120° F, Closes at 90° F,
It has a One Time Open Temp. of 145° F.
5 KW, 230 V, Resistance 9.31 Ohms + - 5%.
Has 1 Limit Switch, Opens at 130° F, Closes at 100° F,
It has a One Time Open Temp. of 155° F.
VPAK 24K BTUs Models:
2.5 KW, 230 V, Resistance 18.61 Ohms + - 5%.
Has 2 Limit Switches, Primary Opens at 155° F,
Closes at 125° F, Secondary's Open Temp. is 200° F.
3.4 KW, 230 V, Resistance 13.68 Ohms + - 5%.
Has 2 Limit Switches, Primary Opens at 155° F,
Closes at 125° F, Secondary's Open Temp. is 200° F.
5 KW, 230 V, Resistance 9.31 Ohms + - 5%.
Has 2 Limit Switches, Primary Opens at 155° F,
Closes at 125° F, Secondary's Open Temp. is 200° F.
7.5 KW, 230 V (composed of 2, 3.7 KW Elements)
Each Has a Resistance of 12.41 Ohms + - 5%.
Each Has 2 Limit Switches, Primary Opens at 165° F,
Closes at 135° F With a 1 time Open Temp. of 210° F.
Secondary Limit's Open Temp. is 200° F.
10 KW, 230 V (composed of 2, 5 KW Elements)
Each Has a Resistance of 9.31 Ohms + - 5%.
Each Has 2 Limit Switches, Primary Opens at 165° F,
Closes at 135° F With a 1 time Open Temp. of 210° F.
Secondary Limit's Open Temp. is 200° F.
NOTE: Always replace with an exact replacement.
TESTING THE HEATING ELEMENTS AND
LIMIT SWITCHES
WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.
Testing of the heating elements can be made with an
ohmmeter or continuity tester across the terminals after
the power wires have been removed. Test the limit switch
for continuity across its input and output terminals.Test
below the limit switch's reset temperature.
DRAIN PAN VALVE
During the cooling mode of operation, condensate which
collects in the drain pan is picked up by the condenser fan
blade and sprayed onto the condenser coil. This assists
in cooling the refrigerant plus evaporating the water.
During the heating mode of operation, it is necessary that
water be removed to prevent it from freezing during cold
outside temperatures. This could cause the condenser
fan blade to freeze in the accumulated water and prevent
it from turning.
To provide a means of draining this water, a bellows type
drain valve is installed over a drain opening in the base
pan.
This valve is temperature sensitive and will open when
the outside temperature reaches 40°F. The valve will
close gradually as the temperature rises above 40°F to
fully close at 60°F.
Bellows Assembly
Drain Pan Valve
23