Step 8 -- Install Gas Piping -- Unit is equipped for
use with natural gas. Refer to local building codes, or in the
absence of local codes, to ANSI Z223.1-1atest year and
addendum Z223.1A-latest year entitled HFGC. In Canada, in-
stallation must be in accordance with the CANI.BI49.1 and
CAN 1.B 149.2 installation codes for gas burning appliances.
Support gas piping as shown in the table in Fig. 10. For
example, a JV4-in. gas piping must have one field-fabricated
support beam every 8 11. Therefore, an 18-1l long gas pipe
would have a minimum of 3 support beams. See Fig. 10 for
typical pipe guide and locations of external manual gas shutoff
valve.
Install field-supplied manu_fl gas shutoff valve with a l/8-in.
NPT pressure tap for test gage connection at unit. The pressure
tap is located on the gas manifold, adjacent to the gas v_flve.
Field gas piping must include sediment trap and union. See
Fig. 11. Inst_dl a field-supplied gas regulatol:
Do not pressure test gas supply while connected to unit.
Always disconnect union before servicing. Damage to
equipment or personal injury may result.
,m X _'1
GAS I
{' I 'MANUALaASREGU TOR*I
/ BASEUNI T _J_TOFF VALVE* ,_
.......................................I }1
T-q T OR,P E PERNFGC*
B sE+L ]i '-"OO CUR /
FIELD-FABRICATED
SUPPORT*
FROM GAS METER
LEGEND
NFGC -- National Fuel Gas Code
*Field supplied.
NOTE: Follow all local codes.
STEEL PIPE NOMINAL I SPACING OF SUPPORTS
DIAMETER (in.) I X DIMENSION (ft)
1/2 6
3/4 or 1 8
11/4 or larger 10
Fig. 10 -- Gas Piping Guide (With Accessory
Thru-the-Curb Service Connections)
MANUAL SHUTOFF
(FIELD SUPPLIED)
rq-i
f SUPPLY
PRESSURE TAP
(1/8" NPT PLUG)
UNIT UN]OL_'_N _ "+--'-- SEDIMENT TRAP
Fig. 11 -- Field Gas Piping
I IMPORTANT: Natural gas pressure at unit gas connection I
must not be less than 5.0 in. wg or greater than 13.0 in. wg
I
for all heat sizes.
Size gas-supply piping for 0.5-in. wg maximum pressure
diop. Do not use supply pipe smaller than unit gas connection.
Step 9 -- Make Electrical Connections
FIELD POWER SUPPLY -- All 208/230-v units _u'e factory
wired for 230-v power supply. If the 208/230-v unit is to be
connected to a 208-v power supply, the transformer must be re-
wired by moving the black wire with the l/4-in, female quick
connector flom the 230-volt connection and moving to
the 200-volt l/4-in, male termimd on the primary side of the
transformel:
Refer to unit label diagram for additional information. All
field wiring must comply with NEC (National Electrical Code)
tuld local codes. Size wire based on MCA (Minimum Circuit
Amps) on the unit informative plate. Leads are provided for
field wire connections. Use UL (Underwriters' Laboratories)
approved copper/aluminum connectol:
When installing units, provide safety disconnect per NEC
Article 440 or local codes. For non-fused disconnects, size the
disconnect according to the sizing &_ta provided in the electri-
cal data tables. Ifa lilsed disconnect is used, determine the min-
imum size for the switch based on the disconnect sizing data
provided in the electric:d data tables and then coordinate the
disconnect housing size to accommodate the Maximum Over-
current Protection (MOCP) device size as maned on the unit
infonnative plate. See Tables 2A and 2B.
See Fig. 12 for power wiring connection to unit leads and
equipment ground.
Route power and ground lines through control box end
panel or unit basepan (see Fig. 3) to connections as shown on
unit wiring diagram and Fig. 12. Factory leads may be wired
directly to the disconnect.
The correct power phasing is cdtic:d to the operation of the
scroll compressors. An incorrect phasing will result in
compressor shutdown on thermal overload and possible
&_mage to compressol: Should this occm; power phase cor-
rection must be made to the incoming powec
Unit cabinet must have an uninterrupted, unbroken electri-
cal ground to minimize the possibility of pel_onal injury if
an electrical fault should occm: This ground may consist of
electric_d wire connected to unit ground lug in control com-
partment, or conduit approved for electrical ground when
installed in accor&mce with NEC; ANSI/NFPA (National
Fire Protection Association), latest edition, and local elec-
triced codes. Do not use gas piping as an electrical ground
Failure to follow this warning could result in the installer
being liable for personal injury of others.
Field winng must conform to temperature limitations for
type "T" wire. All field wiring must comply with NEC and
local requirements.
Operating voltage to compressor must be within voltage
range indicated on unit nameplate. On 3-phase units, voltages
between phases must be balanced within 2%.
Unit failure as a result of operation on improper line voltage
or excessive phase imbalance constitutes abuse and may cause
&image to electrical components.
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