Bryant DURAPAC PLUS SERIES 542J User Manual
Page 7
—
7
—
VI. STEP 6 — MAKE ELECTRIC CONNECTIONS
A. Field Power Supply
Unit is factory wired for voltage shown on nameplate.
When installing units, provide a disconnect of adequate size
per NEC (National Electrical Code) requirements (Table 2).
All field wiring must comply with NEC and local
requirements.
Route power lines through control box access panel or unit
basepan (Fig. 4 and 5) to connections as shown on unit wir-
ing diagram and Fig. 11.
Transformers no. 1 and 2 are wired for 230-v unit. If 208/
203-v unit is to be run with 208-v power supply, the trans-
formers must be rewired as follows:
1. Remove cap from red (208 v) wire.
2. Remove cap from orange (230 v) spliced wire.
3. Replace orange wire with red wire.
4. Recap both wires.
IMPORTANT:
BE CERTAIN UNUSED WIRES ARE
CAPPED. Failure to do so may damage the transformers.
Operating voltage to compressor must be within voltage
range indicated on unit nameplate. On 3-phase units, volt-
ages between phases must be balanced within 2% and the
current must be balanced within 10%.
Use the following formula to determine the percentage of
voltage imbalance.
Percentage of Voltage Imbalance
EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
Determine maximum deviation from average voltage:
(AB) 457 – 452 = 5 v
(BC) 464 – 457 = 7 v
(AC) 457 – 455 = 2 v
Maximum deviation is 7 v.
Determine the percent voltage imbalance:
This amount of phase imbalance is satisfactory as it is below
the maximum allowable 2%.
IMPORTANT:
If the supply voltage phase imbalance is
more than 2%, contact your local electric utility company
immediately.
Unit failure as a result of operation on improper line voltage
or excessive phase imbalance constitutes abuse and may
cause damage to electrical components.
= 100 x
max voltage deviation from average voltage
average voltage
Average Voltage =
455 + 464 + 455
3
=
1371
3
= 457
Percentage of Voltage Imbalance= 100 x
7
457
= 1.53%
Shaded area indicates block-off panels.
NOTE: Dimensions A, A
′
and B, B
′
are obtained from field-supplied
ceiling diffuser.
Fig. 8 — Concentric Duct Details
NOTE: Do not drill in this area, as damage to basepan may result in
water leak.
Fig. 7 — Concentric Duct Air Distribution
(542J180 Shown)
NOTE: Do not drill in this area, as damage to basepan may result in
water leak.
Fig. 6 — Air Distribution — Thru-the-Bottom
(542J180 Shown)