Units Without Thru- - Base Connections; All Units; Field Control Wiring; Thermostat - Bryant 549J Series Installation Instructions Manual

Fig. 26 - - Thru- - Base Connection Fittings
Check tightness of connector lock nuts before connecting
electrical conduits.
Field- - supplied and field- - installed liquid tight conduit
connectors and conduit may be attached to the connectors
on the basepan. Pull correctly rated high voltage and low
voltage through appropriate conduits. Connect the power
conduit to the internal disconnect (if unit is so equipped)
or to the external disconnect (through unit side panel). A
hole must be field cut in the main control box bottom on
the left side so the 24- - v control connections can be made.
Connect the control power conduit to the unit control box
at this hole.
Units without Thru- - Base Connections —
1. Install power wiring conduit through side panel open-
ings. Install conduit between disconnect and control
box.
2. Install power lines to terminal connections as shown
in Fig. 18.
All Units —
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. On
3- - phase units, voltages between phases must be balanced
within 2% and the current within 10%. Use the formula
below to determine the percent of voltage imbalance.
max voltage deviation from average voltage
% Voltage
= 100 x
Imbalance
Example: Supply voltage is 230-3-60
AB = 224 v
BC = 231 v
AC = 226 v
(224 + 231 + 226)
Average Voltage =
3
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.
% Voltage Imbalance
= 100 x
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
C13412
average voltage
681
= = 227
3
4
= 1.76%
227
IMPORTANT: If the supply voltage phase imbalance is more than
2%, contact your local electric utility company immediately.
Operation on improper line voltage or excessive phase
imbalance constitutes abuse and may cause damage to
electrical components. Such operation would invalidate
any applicable Bryant warranty.
Field Control Wiring —
The 549J unit requires an external temperature control
device. This device can be a thermostat emulation device
provided as part of a third- - party Building Management
System or the RTU Open controller (RTU Open controller
is available as a factory- - installed option only).
Thermostat —
Select a Bryant- - approved accessory thermostat. When
electric heat is installed in the 549J unit, the thermostat must
be capable of energizing the G terminal (to energize the
Indoor Fan Contactor) whenever there is a space call for
heat (energizing the W1 terminal). Accessory thermostats
listed on the unit price pages can provide this signal but they
are not configured to enable this signal as shipped.
Typical

Thermostat

Connections
C
G
W2
(Note 2)
W1
O/B/Y2
(Note 1)
Y1
R
Note 1: Typical multi-function marking. Follow manufacturer's configuration
instructions to select Y2. Do not configure for O output.
Note 2: W2 connection not required on units without electric heating.
Field Wiring
Fig. 27 - - Typical Low- - Voltage Control Connections
Install the accessory thermostat according to installation
instructions included with the accessory.
Locate the thermostat accessory on a solid wall in the
conditioned space to sense average temperature in
accordance with the thermostat installation instructions.
If the thermostat contains a logic circuit requiring 24- - v
power, use a thermostat cable or equivalent single leads of
different colors with minimum of seven leads. If the
thermostat does not require a 24- - v source (no "C"
connection required), use a thermostat cable or equivalent
with minimum of six leads. Check the thermostat
installation instructions for additional features which
might require additional conductors in the cable.
19
Central
Terminal
Board
X
C
T
H
G
E
R
W2
M
O
W1
S
T
Y2
A
T
Y1
R
C09012