DEFROST
The unit has a demand defrost control.
During troubleshooting, defrost can be initiated by shorting
defrost test pins on the module. The pins are about 1/2" long
and mounted on the upper right hand side of the defrost
control.
TUBING CONNECTIONS
Sweat-connect systems must use field supplied, clean, dehy-
drated refrigeration-grade copper tubing.
Quick-connect systems must use pre-charged refrigerant line
sets (quick-connect couplings) designated for the respective
unit size and available from CES. Pre-charged lines with ex-
cess tubing should be coiled horizontally in an inconspicuous
location to avoid oil trapping.
Stub kits are available to field fabricate quick connect line sets
or to connect mix-matched units and coils.
Unit should be installed only with approved system combina-
tions (indoor coil/outdoor unit) specified in Technical Guide.
See Application Data,"General Piping Recommendations and
Refrigerant Line Length," for vapor and liquid line sizing, cal-
culation of liquid line pressure loss or gain, determination of
vapor line velocity, elevation limitations, orifice corrections,
system charging, traps, etc.
Total line lengths are limited to 75 feet due to the storage
capacity of the accumulator. Systems with total line lengths
over 50 feet must be provided with a low voltage start kit.
Elevation differences are limited to:
Indoor Above Outdoor ....... 50 ft.
Outdoor Above Indoor ....... 50 ft.
Systems with liquid line pressure loss or gain greater than 11
psi must be provided with corrected orifice size.
Inter-connecting refrigerant lines should be sized to match the
factory supplied fittings. Liquid lines must NEVER be increased
or decreased. Vapor lines may be increased one size to mini-
mize pressure drop as long as a velocity of at least 1000 feet
per minute is maintained.
Additional charge is required for inter-connecting piping greater
than 15 feet for sweat units and some indoor coil matches.
The lines should be installed so that they will not obstruct
service access to the coil, air handling system or filter. Install
the lines with as few bends as possible. Care must be taken
not to damage the couplings or kink the tubing. Care must also
be used to isolate the refrigerant lines to minimize noise
transmission from the equipment to the structure.
Tape and suspend the refrigerant lines as shown. DO NOT
allow metal-to-metal contact.
Use PVC piping as a conduit for all underground installations
as shown below. Buried lines should be kept as short as
possible to minimize the build up of liquid refrigerant in the
vapor line during long periods of shutdown.
LIQUID
LINE
TAPE
SHEET
METAL
HANGER
INSULATED
VAPOR LINE
FIGURE 4 - TUBING HANGER
TO INDOOR COIL
TO OUTDOOR UNIT
LIQUID LINE
CAP
PVC
CONDUIT
INSULATED
VAPOR LINE
FIGURE 5 - UNDERGROUND INSTALLATION
515.26-N1Y
Central Environmental Systems
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