Refrigerant System - Lennox 13HPX Series Unit Information

(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 − Drier
A filter drier designed for all 13HPX 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 2 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
R−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
II − REFRIGERANT SYSTEM
13HPX COOLING CYCLE (SHOWING MANIFOLD GAUGE CONNECTIONS)
DEFROST THERMOSTAT
EXPANSION/CHECK
VALVE
LOW HIGH
PRESSURE PRESSURE
GAUGE MANIFOLD
TO
LIQUID LINE
R−410A
SERVICE
DRUM
PORT
OUTDOOR UNIT
DISTRIBUTOR
BIFLOW
OUTDOOR
FILTER / DRIER
COIL
MUFFLER
COMPRESSOR
NOTE − ARROWS INDICATE DIRECTION OF REFRIGERANT FLOW
FIGURE 10
Page 8
than 4 psig. To safeguard against moisture entering the
system follow the steps in section III − sub section
C − "Evacuating the System" when replacing the drier.
H − Crankcase Heater HR1 & Thermostat
S40 (options)
Crankcase heater HR1 is an option for all size units, while
thermostat S40 is an option for 5 ton units only. HR1 is a 40
watt heater that prevents liquid from accumulating in the
compressor. In the 13HPX−060 (5 ton unit) HR1 is con-
trolled by thermostat S40 located in the liquid line. When
liquid line temperature drops below 50° F, S40 closes ener-
gizing HR1. S40 will open once liquid line temperature
reaches 70°, de−energizing HR1.
TABLE 2
KIT CONTENTS
10N46 − Refrig-
Checkmate−RT700
erant Analysis
10N45 − Acid Checkmate−RT750A (three
Test Tubes pack)
10N44 − Mois- Checkmate − RT751 Tubes
ture Test Tubes (three pack)
74N40 − Easy Checkmate − RT752C Tubes
Oil Test Tubes (three pack)
74N39 − Acid
Sporian One Shot − TA−1
Test Kit
REVERSING VALVE
SUCTION
SERVICE
VAPOR
PORT
LINE
VALVE
EXPANSION/CHECK
VALVE
TUBE SHELF
LIFE
2 − 3 years @
room tempera-
ture. 3+ years re-
frigerated
6 − 12 months @
room tempera-
ture. 2 years re-
frigerated
2 − 3 years @
room tempera-
ture. 3+ years re-
frigerated
INDOOR UNIT
INDOOR
COIL