Manual

41
Wire control signals to the unit’s low
voltage terminal block located in the
controls compartment.
If any factory installed wiring must be
replaced, use a minimum 105°C type AWM
insulated conductors.
Thermostat Control Wiring
If a thermostat is used for unit control,
thermostat should be located on an inside
wall 4-5 feet above the floor where it will
not be subjected to drafts, sun exposure, or
heat from electrical fixtures of appliances.
Control wiring must deliver adequate
voltage to components to assure proper
operation. Control voltage returning from
controller circuit must be a minimum of 21
VAC. To assure proper wiring use the
following chart to determine the allowable
wiring distances.
Table 4 - Control Wiring
Wire Size (Stranded)
- Copper Conductors
Only
Total Wire Distance
Allowable
20 AWG
200 ft
18 AWG
350 ft
16 AWG
500 ft
14 AWG
750 ft
12 AWG
1250 ft
Take the total wire distance allowable and
divide by the number of wires to be
connected. This indicates the distance
allowable for that size wire. The wiring to
the unit must not exceed the total wire
distance allowable. If the voltage at the
connectors is less than 21 VAC, isolation
relays must be installed. If under external
control 21 VAC must be field verified.
All external devices must be powered via a
separate external power supply.
Example:
A total of 8 wires must be pulled 75ft to
control the unit. What size wire should be
used?
According to the Table 3, 16 AWG allows
for 63ft (500 ft/8 wires) and 14 AWG allows
for 94ft (750 ft/8 wires). Thus, 14 AWG
should be used.
Gas Heating
Verify the unit nameplate agrees with the
proper gas supply type and amount.
Gas piping must be installed in accordance
with local codes, or in the absence of local
codes, installation must conform to the
current (United States) National Fuel Gas
Code ANSI-Z223.1/NFPA 54 or the current
(Canada) National Fuel & Propane
Installation Code CSA B149.1 or B149.2.
Table 5 - 2-6 ton Gas Connections
Model
Option
B2
Input
MBH
Connections
Quantity
Size
1
60.0
1
1/2”
3
100.0
5
140.0
7
160.0
FOR YOUR SAFETY
Read the entire gas heating
installation section of this manual
before beginning installation of the
gas heating section.
If you do not follow these instructions
exactly, a fire or explosion may result
causing property damage, personal
injury, or loss of life.
WARNING