Table of Contents
Advertisement
NOMINAL
INTERNAL
IRON PIPE
DIAMETER
10
SIZE (IN.)
(IN.)
(3)
1/2
.622
175
3/4
.824
360
1
1.049
680
1--- 1/4
1.380
1400
1--- 1/2
1.610
2100
*Capacity of pipe in cu ft of gas per hr for gas pressure of 0.5 psig or less. Pressure drop of 0.5 ---IN. W.C. (based on a 0.60 specific gravity gas). Refer to Table 2
and National Fuel Gas Code NFPA 54/ANSI Z223.1.
{ This length includes an ordinary number of fittings.
Step 10 — Install Electrical Connections
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
The unit cabinet must have an uninterrupted, unbroken
electrical ground. This ground may consist of an electrical
wire connected to the unit ground screw in the control
compartment, or conduit approved for electrical ground
when installed in accordance with NFPA 70 (NEC) (latest
edition) (in Canada, Canadian Electrical Code CSA C22.1)
and local electrical codes.
CAUTION
!
UNIT COMPONENT DAMAGE HAZARD
Failure to follow this caution may result in damage to the
unit being installed.
1. Make all electrical connections in accordance with NFPA
70 (NEC) (latest edition) and local electrical codes
governing such wiring. In Canada, all electrical
connections must be in accordance with CSA standard
C22.1 Canadian Electrical Code Part 1 and applicable
local codes. Refer to unit wiring diagram.
2. Use only copper conductor for connections between
field- -supplied electrical disconnect switch and unit. DO
NOT USE ALUMINUM WIRE.
3. Be sure that high- -voltage power to unit is within
operating voltage range indicated on unit rating plate. On
3- -phase units, ensure phases are balanced within 2
percent. Consult local power company for correction of
improper voltage and/or phase imbalance.
4. Insulate low- -voltage wires for highest voltage contained
within conduit when low- -voltage control wires are in
same conduit as high- -voltage wires.
5. Do not damage internal components when drilling
through any panel to mount electrical hardware, conduit,
etc.
High- - Voltage Connections
When routing power leads into unit, use only copper wire between
disconnect and unit. The high voltage leads should be in a conduit
until they enter the duct panel; conduit termination at the duct
panel must be watertight.
The unit must have a separate electrical service with a
field- -supplied, waterproof disconnect switch mounted at, or within
sight from, the unit. Refer to the unit rating plate, NEC and local
codes for maximum fuse/circuit breaker size and minimum circuit
amps (ampacity) for wire sizing.
Table 2 – Maximum Gas Flow Capacity*
20
30
40
50
(6)
(9)
(12)
(15)
120
97
82
73
250
200
170
151
465
375
320
285
950
770
600
580
1460
1180
990
900
LENGTH OF PIPE FT (m)†
60
70
80
90
(18)
(21)
(24)
(27)
66
61
57
53
138
125
118
110
260
240
220
205
530
490
460
430
810
750
690
650
The field- -supplied disconnect switch box may be mounted on the
unit over the high- -voltage inlet hole when the standard power and
low- -voltage entry points are used (See Fig. 3 and 4 for acceptable
location).
NOTE:
Field supplied disconnect switch box should be
positioned so that it does not cover up any of the unit gas
combustion supply air louvers.
See unit wiring label (Fig. 14, 15 and 16) and Fig. 10 for reference
when making high voltage connections. Proceed as follows to
complete the high- -voltage connections to the unit.
Single phase units:
1. Run the high- -voltage (L1, L2) and ground lead into the
control box.
2. Connect ground lead to chassis ground connection.
3. Locate the black and yellow wires connected to the line side
of the contactor (if equipped).
4. Connect field L1 to black wire on connection 11 of the
compressor contactor.
5. Connect field wire L2 to yellow wire on connection 23 of
the compressor contactor.
Three- -phase units:
1. Run the high- -voltage (L1, L2, L3) and ground lead into the
control box.
2. Connect ground lead to chassis ground connection.
3. Locate the black and yellow wires connected to the line side
of the contactor (if equipped).
4. Connect field L1 to black wire on connection 11 of the
compressor contactor.
5. Connect field wire L3 to yellow wire on connection 13 of
the compressor contactor.
6. Connect field wire L2 to blue wire from compressor.
Special Procedures for 208- - v Operation
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Make sure the power supply to the unit is switched OFF and
install lockout tag. before making any wiring changes. With
disconnect switch open, move black wire from transformer
(3/16 in. [4.8 mm]) terminal marked 230 to terminal marked
208. This retaps transformer to primary voltage of 208 vac.
11
100
125
150
175
(30)
(38)
(46)
(53)
50
44
40
—
103
93
84
77
195
175
160
145
400
360
325
300
620
550
500
460
200
(61)
—
72
135
280
430
Advertisement
Table of Contents
