EMI WLHA - Manual (Page 33)

www.enviromaster.com 33 WLCA/WLHA High Wall Evaporator
q:
The system has just been installed us-
ing an EMI indoor unit and a non-EMI
condenser. There is no display and the
unit will not operate.
A:
EMI air handlers are manufactured with
a low
Volt transformer installed. When
connecting an EMI evaporator to a non-
EMI condenser, check to ensure that
there is no 24
V control transformer in
the outdoor unit. Only one transformer
is required. If both the indoor unit and
outdoor unit contain a transformer, one
must be removed from the system.
q:
The condenser will not start although
the indoor unit appears normal. What
should I do?
A:
At the indoor unit, make sure that the
control is in cooling and the setpoint
temperature is below room temperature.
Next, using a volt meter, check for 24V
across the yellow (Y) and brown (C)
wires. If 24V is present then check for
wiring breaks or improper connections
between the indoor and outdoor units.
A:
Some EMI condensers are equipped
with a manual reset high-pressure
switch. It is located on the high side of
the refrigerant system usually on the
discharge line of the compressor. To
reset, simply push the red button in. If
the switch was tripped there will be a
“click” when it resets.
A:
If the unit is equipped with a condensate
pump check to see if the safety float
has been tripped. This can be done by
first disconnecting both ends of the float
switch. Then with an Ohmmeter, check
for continuity across the switch. If the
switch is open then the pump is not
clearing or the switch may be bad.
troUBLEsHootinG proCEdUrE Continued
frequently Asked questions
q:
The display on the indoor unit is blank.
What should I do?
A:
Check the power supply (see “Power
supply check” Section). If the unit still
fails to turn on via the On/off button
then inspect the control box for any
apparent wires that may have come
loose during shipping. Also inspect the
circuit boards for burnt components. If
no obvious problem can be found then
replace all circuit boards including the
unit keypad. Do not attempt to trouble
shoot the individual circuit boards.
q:
The display tends to flicker at times. Is
this normal?
A:
A small amount of flickering of the dis-
play is normal. Depending on the room
lighting, flickering may be noticeable at
some times more than others.
q:
How long will the fan run?
A:
While the unit is in cooling or heating
and auto fan mode is selected, Fan
speed will be determined by the micro-
processor and speed adjustment will be
made according to room and setpoint
temperatures. The fan will switch to
High
speed when room temperature
deviates by more than two degrees
from setpoint. The fan will switch to Low
speed if the deviation is one degree.
When the room temperature reaches
setpoint temperature the heat/cool call
is dropped. The fan will then stay on for
an additional 60 seconds to purge unit
of any residual energy. If High or Low
is selected then the fan will operate
continuous regardless of set point or
room temperatures.
q:
What causes my indoor unit to freeze-up?
A:
Evaporator freeze up is usually the
symptom of another problem. Units with
infrared compatible, unit mounted con-
trols are equipped with freeze protection