Instruction Manual

52
Total Wire Distance Allowable =
(Quantity of Control Wires) x
(Control Wire Distance)
Take the total wire distance allowable and
divide by the quantity 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 a
control the unit. What size wire should be
used?
According to the Table 8, 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 9 - 6-8 and 10 ton Gas Connections
Model
Option
B2
Input
MBH
Connections
Quantity
Size
2
90.0
1
1/2” NPT
K
150.0
L
210.0
3/4” NPT
Table 10 - 9 and 11-15 ton Gas Connections
Model
Option
B2
Input
MBH
Connections
Quantity
Size
F
195.0
1
3/4” NPT
G
292.5
6
390.0
Table 11 - 16-25 and 30 ton
Gas Connections
Model
Option
B2
Input
MBH
Connections
Quantity
Size
4
270
1
3/4” NPT
8
405
1” NPT
C
540
Table 12 - 26 and 31-70 ton
Gas Connections
Model
Option
B2
Input
MBH
Connections
Quantity
Size
*A
540
2
3/4” NPT
*B
780
C
540
1
1-1/2”
NPT
D
810
E
1080
*Obsolete
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