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Installer's Guide
L. PRESSURE TEST:
•
Using dry nitrogen, pressurize the field piping and indoor coil
to the lower of the maximum operating pressures listed on the
name plates of the indoor and outdoor units (likely 600 psi).
•
The test pressure after removal of the pressure source shall
be maintained for at least one (1) hour with no decrease of
pressure indicated by the test gauge, with the test gauge
resolution not exceeding 30 psi.
•
Check for leaks by using a soapy solution at each field-
made joint.
Note: Remove nitrogen pressure and repair any leaks before
continuing.
M. VACUUM TEST:
Important: Do not open the service valves until the refrigerant
lines and indoor coil leak check and evacuation are
complete.
•
Evacuate until the micron gauge reads no higher than 350
microns, then close off the valve to the vacuum pump.
•
Observe the micron gauge. Evacuation is complete if the
micron gauge does not rise above 500 microns in one (1)
minute and 1500 microns in ten (10) minutes.
•
Once evacuation is complete, blank off the vacuum pump
and micron gauge, and close the valve on the manifold gauge
set.
All procedures for charging the system with refrigerant shall be
according to the instructions provided by the manufacturer of
the outdoor unit.
Important: Under no circumstances shall potential sources of
ignition be used in the searching for or detection of
refrigerant leaks.
12
After charging the system, all indoor field-made joints of the field
piping shall be checked for refrigerant leaks using an electronic
leak detector calibrated for R-454B having a sensitivity of 5 grams
per year or better.
N. CONDENSATE DRAIN PIPING:
Condensate drain connections are located in the drain pan at
the bottom of the coil/enclosure assembly. The female threaded
fitting protrudes outside of the enclosure for external connection.
A field fabricated trap is not required for proper drainage due to
the positive pressure of the furnace; however, it is recommended
to prevent efficiency loss of conditioned air.
1.
The drain hole in the drain pan must be cleared of all insulation.
2.
Insulate the primary drain line to prevent sweating where
dew point temperatures may be met. (Optional depending
on climate and application needs)
3.
Connect the secondary drain line to a separate drain line
(no trap is needed in this line).
O. CLEANING THE COIL:
The two piece door allows removal of the outer casing doors
without interference from refrigerant or condensate lines.
The foil covered insulation on 5TXC coils should be wiped down
and residual dirt and dust should be vacuumed up to maintain
good air quality. See Figure 17.
The manufacturer's recommendation for coil cleaning is to initially
use only water to wash away debris that may have collected on
and in the coil fin surface. Removing an evaporator coil is the best
way to effectively clean a coil that is heavily contaminated. This
is accomplished by removing the coil from the cabinet, sealing
the liquid and vapor line and using a strong water stream such
as from a garden hose, being careful to prevent fin damage. Use
chemical cleaners, only when necessary.
NOTE:
Refer to Service Guideline, UN-SVG001C-EN, Evaporator
Coil Cleaning and Condensate Drain Maintenance Guide-
lines for important information on cleaning coils with
chemical treatments.
Figure 17
18-AD47D1-1B-EN
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