The Ductless Split System of Choice
Made in Rome, New York, USA
5
fan on the high pressure side of the system.
Multiple compressor units also utilize a single cyling
condenser fan on the high pressure side of the system.
The operating range is 210-275 psi. This enables cool-
ing down to approximately 0° F.
NOTE:
Multiple compressor units use one (1)
fan for all of the compressors.
Heat Pump-
The low ambient option is available on
single zone heat pump systems. These units also utilize a
single cycling condenser fan, with a relay that allows the
fan to run continuously in heating mode.
Multiple compressor heat pump units use a hot gas
bypass method. The system uses an automatic expan-
sion valve (AXV) to prevent coil freeze up. This al-
lows hot gas to bypass to the suction side under low
ambient conditions.
L
OW
A
MBIENT
T
ROUBLESHOOTING
If the condenser motor cycles rapidly or does not op-
erate at all, check for the following:
Power to the motor
Total system undercharge- System cannot obtain
minimum pressures to signal the motor to cycle (refer
to STG for charging information)
If the unit is charged properly and operating under
low ambient conditions (65° dry bulb F or lower), the
motor should cycle rapidly between 210 (motor off)
and 275 (motor on) psi on the high side.
If the outdoor temperatures coincide with EMI sys-
tem performance charts (65° F and above), in most
cases, the motor will run continuously. In some cases,
under normal operating conditions the motor may have
periods when it will cycle in the 65-75° F temperature
range. This is not abnormal and is not cause for alarm.
CONDENSATE PUMPS & DRAIN
EMI recommends one trap (required on the TBC/TBH
models) for the drain line after it leaves the unit. Never
double trap the drain line. Pour water into the drain pan af-
ter installation to ensure proper drainage.
When installing the condensate line, make certain
the unit is not installed at a distance/height that is
greater than the capability of the factory installed pump
(see Pump Specifications). EMI factory installed
pumps have a maximum lift of 4 feet from the bottom
of the unit.
NOTE:
Before completing installation, test
pump action.
EMI offers external pumps for installations that re-
quire more than 4 feet of lift.
SYSTEM TROUBLESHOOTING
If your EMI system does not seem to operate prop-
erly, or the pressure/temperature readings are not correct,
refer to this section and the Troubleshooting Guide in this
manual. Run through the following checklist to properly di-
agnose a problem with your EMI system.
Is the unit switched on?
Are the controls calling for heat or cool?
Is the evap fan running properly?
Is the condenser fan running properly?
Is condenser air flow adequate and unrestricted?
Is the compressor running?
Is subcooling excessive? (see explanation below)
Is superheat too high/low? (see explanation below)
Is the supplied voltage for the unit correct and
within normal tolerances?
Excessive subcooling
is caused by non-condensables
(air/water), overcharge, dirty coil, or a restriction. Purge and
draw vacuum to determine if non-condensables are the prob-
lem. If it doesnt solve the problem, remove refrigerant until
subcooling is no longer excessive. If the system was over-
charged, this will solve the problem. If it does not solve the
problem, check superheat readings.
WARNING!! It is illegal to discharge
refrigerant into the atmosphere. Use
proper reclaiming methods & tools when
installing or servicing equipment.
High superheat
is caused by an undercharge, leak,
or restriction. If refrigerant is added to the system to nor-
malize subcooling and the superheat is still high, then there
is a restriction (possible underfeeding expansion device). If
superheat is no longer high, the system was undercharged.
Locate any leaks and repair. When no leaks are found or
remain, recharge the system.
Low superheat (floodback)
is caused by an over-
charge, overfeeding expansion device, or inefficient com-
pressor. If refrigerant is removed and both subcooling and
super heat readings are normal, the system was overcharged.
Check the efficiency of the compressor if subcooling is low.
If the compressor is normal, the expansion device is over-
feeding.
NOTE:
Condensing units built before January
1, 1994, require the service panel be placed
over the service opening when performing tests
to get true readings.
