Field Power Supply - Carrier WEATHERMAKER 48A2 Installation Instructions Manual

Fig. 18 — Field Gas Piping
Table 7 — 48A Series Staged Gas Control
MODEL NUMBER POSITION
NUMBER OF
STAGES
5
S
5 stages
T
7 stages T
9 stages T
11 stages S
FIELD POWER SUPPLY — Unit is factory wired for volt-
age shown on unit nameplate. See Tables 8A and 8B for elec-
trical data.
Field wiring can be brought into the unit from bottom
(through basepan and roof curb) or through side of unit (corner
post next to control box).
1
A 3 / -in. NPT coupling for field power wiring and a
2
NPT coupling for 24-v control wiring are provided in basepan.
In the side post, there are two 2
LEGEND
FLA — Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps
MCHX — Microchannel Heat Exchanger
MOCP — Maximum Overcurrent Protection
NEC — National Electrical Code
RLA — Rated Load Amps
RTPF — Round Tube Plate Fin Coil
*Fuse or HACR circuit breaker per NEC.
NOTES:
1. In compliance with NEC requirements for multimotor and combination load
equipment (refer to NEC Articles 430 and 440), the overcurrent protective
device for the unit shall be fuse or HACR breaker. The Canadian units may
be fuse or circuit breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is
greater than 2%. Use the following formula to determine the percent of volt-
age imbalance.
% Voltage imbalance
max voltage deviation from average voltage
= 100 x
average voltage
Example: Supply voltage is 460-3-60.
a48-2524
HEAT SIZE
6,7,8
020
025
027
030 Low
035
040
050
035
040 High
050
020
025
High
027
030
060 High
060 Low
3
/ -in.
4
1
/ -in. (sizes 020-035) or 3-in.
2
LEGEND AND NOTES FOR TABLES 8A AND 8B
(sizes 040-060) knockouts for the field power wiring. See
Fig. 4-9. If control wiring is to be brought in through the side of
7
unit, a / -in. diameter hole is provided in the condenser side
8
post next to the control box.
Do not route control wiring in the same conduit as power
wiring.
If disconnect box is mounted to corner post, be careful not
to drill or screw into the condenser coil.
FIELD-INSTALLED DISCONNECT
FACTORY-INSTALLED DISCONNECT
LEGEND
GND — Ground
NEC — National Electrical Code
TB — Terminal Block
Fig. 19 — Field Power Wiring Connections
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =
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 percent of voltage imbalance.
% Voltage Imbalance = 100 x
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.
19
TB1
FIELD
11
POWER
12
SUPPLY
13
EQUIP GND
OPTIONAL
FACTORY-INSTALLED
DISCONNECT
11
12
13
GND
a48-6977
452 + 464 + 455
3
1371
=
3
= 457
7
457
= 1.53%
21
22
23
21
22
23