34
from the 230-v connection and moving it to the 200-v
1
/
4
-in. male
terminal on the primary side of the transformer. Refer to unit label
diagram for additional information.
Voltage to compressor terminals during operation 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
within 10%. Use the following formula to determine the percent
of voltage imbalance. Operation on improper line voltage or ex-
cessive phase imbalance constitutes abuse and may cause damage
to electrical components. Such operation would invalidate any ap-
plicable Carrier warranty.
Example: Supply voltage is 230-3-60
Determine maximum deviation from average voltage.
(AB) 227-224 = 3 v
(BC) 231-227 = 4 v
(AC) 227-226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
This amount of phase imbalance is satisfactory as it is below the maxi-
mum allowable 2%.
CONVENIENCE OUTLETS
Two types of convenience outlets are offered on 48TC models:
non-powered and unit-powered. Both types provide a 125-v GFCI
(ground-fault circuit-interrupter) duplex receptacle rated at 15-A
behind a hinged waterproof access cover, located on the end panel
of the unit. See Fig. 57 and 58.
Fig. 57 — Convenience Outlet Location (Sizes 07-14)
Fig. 58 — Convenience Outlet Location (Sizes 16)
Installing Weatherproof Cover
A weatherproof cover is now required by UL standards for the
factory-installed convenience outlets. This cover cannot be facto-
ry-mounted due to its depth; it must be installed at unit installa-
tion. For shipment, the convenience outlet is covered with a blank
cover plate.
On units with electro-mechanical controls the weatherproof cover
kit is shipped in the unit’s control box. The kit includes the hinged
cover, a backing plate and gasket. On units with a factory-installed
direct digital controller (PremierLink™ or RTU Open), the weath-
erproof cover kit is secured to the basepan underneath the control
box. See Fig. 59.
Disconnect All Power To Unit and Convenience Outlet. Lock-
Out and Tag-Out All Power
Remove the blank cover plate at the convenience outlet; discard
the blank cover.
Loosen the two screws at the GFCI duplex outlet, until approxi-
mately
1
/
2
-in. (13 mm) under screw heads is exposed. Press the
gasket over the screw heads. Slip the backing plate over the screw
heads at the keyhole slots and align with the gasket; tighten the
two screws until snug (do not over-tighten).
Mount the weatherproof cover to the backing plate as shown in
Fig. 59. Remove two slot fillers in the bottom of the cover to per-
mit service tool cords to exit the cover. Check for full closing and
latching.
% Voltage
Imbalance
= 100 x
max voltage deviation from average voltage
average voltage
AB = 224 v
BC = 231 v
AC = 226 v
Average Voltage =
(224 + 231 + 226)
=
681
= 227
3 3
% Voltage Imbalance = 100x
4
= 1.78%
227
IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or
death.
Units with convenience outlet circuits may use multiple dis-
connects. Check convenience outlet for power status before
opening unit for service. Locate its disconnect switch, if appro-
priate, and open it. Lock-out and tag-out this switch, if neces-
sary.
A
B
C
MOTOR
CONTROL
BOX
ACCESS
PANEL
CONVENIENCE
OUTLET
GFCI
PWRD-CO
FUSE
SWITCH
PWRD-CO
TRANSFORMER
CONVENIENCE
OUTLET
GFCI
PWD-CO
FUSE
SWITCH
PWD-CO
TRANSFORMER
DISCONNECT
ACCESS PANEL
To Next Page
Loading...
