Factory-Option Thru-Base Connections (Electrical Connections); Units Without Thru-Base Connections (Electrical Connections); Field Control Wiring; Thermostat - Bryant Preferred Series Installation Instructions Manual

Fig. 38 — Convenience Outlet Utilization Notice Label
FACTORY-OPTION THRU-BASE CONNECTIONS (ELEC-
TRICAL CONNECTIONS)
This service connection kit consists of a
fitting (brass), a / -in. electrical bulkhead connector, and a
1
2
3 / -in. electrical bulkhead connector, all factory-installed in the
4
embossed (raised) section of the unit basepan in the condenser
section. The 3 / -in. bulkhead connector enables the low-voltage
4
control wires to pass through the basepan. The
bulkhead connector allows the high-voltage power wires to pass
through the basepan. See Fig. 21 and 22 on pages 16 and 17.
Check tightness of connector lock nuts before connecting elec-
trical conduits.
Field-supplied and field-installed liquid tight conduit connec-
tors and conduit may be attached to the connectors on the base-
pan. 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 connec-
tions can be made. Connect the control power conduit to the
unit control box at this hole.
UNITS WITHOUT THRU-BASE CONNECTIONS (ELEC-
TRICAL CONNECTIONS)
1. Install power wiring conduit through side panel openings.
Install conduit between disconnect and control box.
2. Install power lines to terminal connections as shown in
Fig. 31 on page 19.
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 formula shown in the example below to de-
termine the percent of voltage imbalance. 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.
% Voltage Imbalance:
max voltage deviation from average voltage
= 100 x
Example: Supply voltage is 230-3-60
A B C
MOTOR
(224 + 231 + 226)
Average Voltage =
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= 100x
1 / -in. NPT gas adapter
2
/ -in. electrical
1
2
average voltage
AB = 224 v
BC = 231 v
AC = 226 v
681
= =
3 3
4
= 1.78%
227
This amount of phase imbalance is satisfactory as it is below the maxi-
mum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.
NOTE: Check all factory and field electrical connections for tightness.

FIELD CONTROL WIRING

The 581J unit requires an external temperature control device.
This device can be a thermostat (field-supplied), a thermostat
emulation device provided as part of a third-party Building Man-
agement System, or the RTU Open Multi-Protocol Controller
(RTU Open is available as a factory-installed option only).

THERMOSTAT

Install a Bryant-approved accessory thermostat according to
installation instructions included with the accessory. For com-
plete economizer function, select a two-stage cooling thermo-
stat. Locate the thermostat accessory on a solid wall in the con-
ditioned space to sense average temperature in accordance with
the thermostat installation instructions. Typical low-voltage
connections are shown in Fig. 39.
Typical
Thermostat
Connections
C
G
W2
W1
O/B/Y2
(Note 1)
Y1
R
Note 1: Typical multi-function marking. Follow manufacturer's configuration
Instructions to select Y2.
Note 2: Y2 to Y2 connection required on single-stage cooling units when
integrated economizer function is desired.
Field Wiring
Fig. 39 — Low-Voltage Thermostat Connections
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 ther-
mostat cable or equivalent with minimum of six leads. Check
the thermostat installation instructions for additional features
which might require additional conductors in the cable.
For wire runs up to 50 ft (15 m), use no. 18 AWG (American
227
Wire Gage) insulated wire [95°F (35°C) minimum]. For 50 to
75 ft (15 to 23 m), use no. 16 AWG insulated wire [95°F
(35°C) minimum]. For over 75 ft (23 m), use no. 14 AWG in-
sulated wire [95°F (35°C) minimum]. Wire sizes larger than
no. 18 AWG cannot be directly connected to the thermostat and
will require a junction box and splice at the thermostat.
Thermostat Wiring, Units Without Thru-Base Connection Kit
Pass the thermostat control wires through the hole provided in
the corner post; then feed the wires through the raceway built
into the corner post to the control box. Pull the wires over to
22
Central
Terminal
Board
X
C
G
W2
W1
Y2
(Note 2)
Y1
R
T
H
E
R
M
O
S
T
A
T