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E − High Pressure Switch (S4)
IMPORTANT
Pressure switch settings for R−410A refrigerant will
be significantly higher than units with R−410A.
An auto-reset, single-pole/single-throw high pressure switch
is located in the liquid line. This switch shuts off the compres-
sor when liquid line pressure rises above the factory setting.
The switch is normally closed and is permanently adjusted to
trip (open) at 590 + 10 psi. See
Pressure Switch Circuit
in
the Defrost Control description.
F − Low Pressure Switch (S87) (option)
An auto-reset, single-pole/single-throw low pressure
switch is located in the suction line. This switch shuts off the
compressor when suction pressure drops below the facto-
ry setting. The switch is closed during normal operating
pressure conditions and is permanently adjusted to trip
(open) at 25 + 5 psi. The switch automatically resets when
suction line pressure rises above 40 + 5 psi. Under certain
conditions the low pressure switch is ignored. See
Pres-
sure Switch Circuit
in the Defrost Control description.
G − Loss of Charge Switch (S24) (option)
The loss of charge switch is NC, auto re−set and located on
the suction line of the compressor. The switch opens when
suction line pressure exceeds the factory setting of 25 + 5
psig and shuts down the compressor. The switch closes at
55 psig + 5.
H − Start Kit (option)
The start kit consist of a potential relay K31 and start capac-
itor C7. The potential relay controls the operation of the
starting circuit. The relay is normally closed when contactor
K1 is de−energized. When K1 is energized, the compressor
immediately begins start up. K31 remains closed during
compressor start up and capacitor C7 remains in the cir-
cuit. When compressor reaches approximately 75% of its
speed, K31 is energized. When K31 energizes, the con-
tacts open and start capacitor C7 is taken out of the circuit.
I − Drier
A filter drier designed for all 14HPX model units is factory
installed in the liquid line. The filter drier is designed to re-
move moisture and foreign matter, which can lead to com-
pressor failure.
Moisture and / or Acid Check
Because POE oils absorb moisture, the dryness of the
system must be verified any time the refrigerant sys-
tem is exposed to open air.
A
compressor oil sample
must be taken to determine if excessive moisture has been
introduced to the oil. Table 3 lists kits available from Lennox
to check POE oils.
If oil sample taken from a system that has been exposed to
open air does not test in the dry color range, the filter drier
MUST be replace.
IMPORTANT
Replacement filter drier MUST be approved for
HFC−410A refrigerant and POE application.
Foreign Matter Check
It is recommended that a liquid line filter drier be replaced
when the pressure drop across the filter drier is greater
than 4 psig. To safeguard against moisture entering the
system follow the steps in section III − sub section
E − "Evacuating the System" when replacing the drier.
J − Crankcase Heater (HR1) & Thermostat
(S40)
Crankcase heater HR1 and thermostat S40 are standard
on 14HPX−036, −042, −048 and −060 units and an option for
the other sizes. HR1 is a 40 watt heater that prevents liquid
from accumulating in the compressor. HR1 is controlled by
thermostat S40 located in the liquid line. When liquid line
temperature drops below 50° F, S40 closes energizing
HR1. S40 will open once liquid line temperature reaches
70°, de−energizing HR1.
TABLE 3
Acid and Moisture Test Kits
KIT
CONTENTS
TUBE SHELF LIFE
10N46 − Refrigerant Analysis
Checkmate−RT700
10N45 − Acid Test Tubes
Checkmate−RT750A (three pack)
2 − 3 years @ room temperature. 3+
years refrigerated
10N44 − Moisture Test Tubes
Checkmate − RT751 Tubes (three
pack)
6 − 12 months @ room temperature. 2
years refrigerated
74N40 − Easy Oil Test Tubes
Checkmate − RT752C Tubes (three
pack)
2 − 3 years @ room temperature. 3+
years refrigerated
74N39 − Acid Test Kit
Sporian One Shot − TA−1
