Table of Contents
Advertisement
Bearings
This fan system uses bearings featuring concentric split
locking collars. The collars are tightened through a cap
screw bridging the split portion of the collar. The cap
screw has a Torx T25 socket head. To tighten the locking
collar: Hold the locking collar tightly against the inner
race of the bearing and torque the cap screw to 65−70
in−lb (7.4−7.9 Nm). See Fig. 7.
Fig. 7 − Tightening Locking Collar
2−SPEED INDOOR FAN MOTOR SYSTEM
WITH VARIABLE FREQUENCY DRIVE
(VFD)
2−Speed Indoor Fan Motor System
NOTE: The 2−Speed Indoor Fan Motor option is not
available on units with the Perfect Humidity™ system.
The 2−Speed Indoor Fan Motor system utilizes a Fan
Speed control board and Variable Frequency Drive (VFD)
to automatically adjust the indoor fan motor speed in
sequence with the unit's ventilation, cooling and heating
operation. Conforming to ASHRAE 90.1 2010 Standard
Section 6.4.3.10.b, during the first stage of cooling
operation the system will adjust the fan motor to provide
two- thirds (2/3) of the design airflow rate for the unit.
When the call for the second stage of cooling is required,
the system will allow the design airflow rate for the unit
established (100%). During the heating mode, the
2−Speed Indoor Fan Motor system will allow total design
airflow rate (100%) operation. During ventilation mode,
the system will operate the fan motor at 2/3 speed.
Identifying Factory Option
This supplement only applies to units that meet the
criteria detailed in Table 1. If the unit does not meet that
criteria, discard this document.
Table 1 – Model−Size / VFD Option Indicator
Position in
Model / Sizes
Model Number
581J 17 − 28
NOTE: See Appendix I for an example of typical Model
Number Nomenclature.
LOCKING COLLAR
T-25 TORX SOCKET
HEAD CAP SCREW
C11505
VDP
FIOP Indicator
17
G, J
Unit Installation with 2−Speed Fan Option
581J Rooftop—Refer to the base unit installation
instructions for standard required operating and service
clearances.
NOTE: The Remote VFD Keypad is a field-installed op
tion. It is not included as part of the Factory installed VFD
option. See "Variable Frequency Drive (VFD) Installa
tion, Setup and Troubleshooting Supplement" for wiring
schematics and performance charts and configuration. See
Fig. 8 for location of the (VFD) as mounted on the various
581J models.
Fig. 8 − VFD Location for 581J 15–27.5 Units
ADDITIONAL VFD INSTALLATION
AND TROUBLESHOOTING
Additional installation, wiring and troubleshooting infor
mation for the VFD can be found in the following manu
als: "Variable Frequency Drive (VFD) Installation, Setup
and Troubleshooting Supplement."
Motor
When replacing the motor, use the following steps. See
Fig. 9.
Fig. 9 − Replacing Belt Driven Motor
6
Variable
Frequency
Drive (VFD)
C11531
BLOWER PULLEY
V-BELT
MOTOR PULLEY
MOTOR
MOTOR MOUNTING
BOLTS (4)
JACK BOLT
JAM NUT (2)
JACK BOLT (2)
C12034
Advertisement
Table of Contents
Troubleshooting
