EMI CAC - Manual (Page 21)

www.enviromaster.com 21 CAC Cassette Evaporator
WARNING
TROUBLESHOOTING PROCEDURE
For CAC Air Handlers With Remote Thermostat Controls
All service should be performed by a
qualified service technician. Before re-
moving access panels or control covers
to expose moving parts of non-insulate
live electrical components for service,
disconnect all high Volt power supplies
to both the indoor unit and outdoor unit.
Failure to do so could result in physical
injury and/or electrical shock.
Figure 1
�� � �����
�
� � ���� �
��� � ���� ��� ���������
�� ��� � �
�
�
�
�
���������
� � � ����
� � ���� �
� � ���� �
������ �
�
�������
� ������ ��� �
���� � � ���� � ������ � ��
��� ��� ��� � ���� ��������
���� ���� � � ��� � �����
�� ������
When troubleshooting the indoor unit,
please refer to the wiring diagram that is
supplied with the equipment. It is located
on the back of the control access panel.
If you are unable to locate the wiring dia-
gram please feel free to call the factory
technical service line at (800) 228-9364
and one can be faxed or mailed. Please
have the full model and serial number
available prior to calling.
EMI America Series evaporators are de-
signed to operate with EMI America Se-
ries condensers. The evaporator (indoor
unit) and condenser (outdoor unit) are to
be independently connected to the electri-
cal service panel and protected by sepa-
rate time delay fuse or HACR breakers.
(See the unit name plate for the correct
breaker type and size). The indoor and
outdoor units are also connected to each
other via a 24V interconnect wiring. A
transformer provides the low Volt power
source for the controls. The number of low
Volt interconnect conductors will be three
to five depending on heating options and
or thermostat selection. Interconnect wire
should be at least 18awg. Refer to the
unit wiring diagram for the interconnect
diagram that matches your system.
Power Supply Check
Power supply check
When troubleshooting any EMI product,
it is important to first check the rating
plate for proper field Voltage and breaker
size. Secondly using a Voltmeter check
the incoming power supply to see that it
agrees with the rating plate. The incoming
power should not exceed the nameplate
Voltage. Also, the incoming power should
not be below the minimum Voltage stated
on the rating plate (197V for units rated
208/230V).
A check for low Voltage power should also
be made. By placing a Voltmeter across
low Volt terminals “R” and “C” at the indoor
unit, there should be a reading of 24V.