1
Section A - Installation
A1. AC Voltage
The unit is a 115VAC, 60Hz appliance. The proper operat-
ing range is between 103 and 126.5 volts AC. The voltage
reading should be taken at the unit power supply leads.
One test should be performed when the unit is turned OFF
and another with it running under load. If the voltage is not
within the proper operating range, it must be corrected be-
fore operation of the unit.
This is an energized circuit. Shock can oc-
cur if not tested properly. Testing to be done
by a qualified service technician.
Check for proper AC volts at the connections at the units
electronic control box on roof mounted units and at the
connections at the electric box on basement units.
The dual units (Models 39224 and 39424) have two AC
volt circuits. Verify that Circuit 1 is wired into CIR 1 termi-
nal block and Circuit 2 is wired into CIR 2 terminal block.
Check for proper AC volts at each terminal block.
A1a. AC Control Voltage
AC control voltage is supplied by the transformer for the
control circuits on the following units: 39025.XXX,
39035.XXX and 39045.XXX. Se Section C14- Transform-
ers on page 34.
A2. DC Volts
On certain models of electronic controlled air conditioners
and heat pumps, DC volts must be supplied to the control
board. The operational range is 10 to 16 VDC. If the DC
voltage is below 10 VDC, you could experience improper
operation of the components within the main board.
A2a. Analog Control System
A DC voltage supply is wired to the control board. The
operating range is 10-16 Volts DC, with a maximum cur-
rent draw of 0.250 Amps.
To check DC volts, first check the voltage between the red
(+12) positive and black (-12) negative, at the connections
on the Analog Control Box on the roof top unit.
FIG. A1
If a furnace is to be operated by the Analog Control Sys-
tem, the furnace thermostat leads are connected to the
blue/white striped wires out of the Analog Control Box. The
furnace wires can be connected to either wire as polarity is
not important. DC voltage is required by the Analog Con-
trol Board on one of the two wires for furnace operation.
A2b. Comfort Control Center System
A DC volt supply is required for the operation of the Com-
fort Control Center. The operational range is 10 to 30 volts
DC. If DC volts are outside of the operating range, you
could experience improper or erratic operation. To check
DC volts, first check the incoming DC volts between the
red (+) positive and black (-) negative, at the connections
on the Comfort Control Center control box on roof top units
or at the connections at the electric box of basement units.
A3. Field Wiring
If the unit’s compressor or fan fails to operate, chances are
it is not receiving proper power. Be sure the power cord is
plugged in and fuses ore breakers are ope.
Note:
Many customers use extremely long power cords
that are undersized. If possible, ask the owner to hook up
the RV just like it was when the problem occurred. See
FIG. A2
FIG. A2
Make note of the wire size and compare it to the chart for
wire sizing. See Section A1a - AC Control Voltage.
CURRENT
WIRE SIZE
IN
AMPS
16
14
12
10
8
6
LENGTH IN FEET
5
47
76
121
192
216
486
10
38
60
96
153
243
15
25
40
64
102
162
20
30
48
76
121
Manual
Compliments
of
Northwest
RV
Supply
Printed
From
http://www.nwrvsupply.com
