Troubleshooting guide, Correct, Incorrect – Greenheck Duct Heaters Series IDHB and IDHC (478052) User Manual
Page 6
Troubleshooting Guide
A duct heater must be installed according to the
installations instructions, wiring diagram and labeling
supplied with the heater.
Listed below are some important items when installing
an electric duct heater:
1. Never operate a duct heater without airflow.
The heater must always be interlocked with
the fan. This may be accomplished by either
an airflow switch or fan interlock relay.
2. Never operate heater without achieving at
least the minimum airflow required. Always
refer to the installation instructions and the
nameplate label to determine minimum air
velocities based on inlet air temperature. If
the minimum airflow requirements are not
present the heater will not function properly
and safely
(see Figure 1).
3. Never operate the heater with uneven
airflow. The minimum airflow requirements
must be present at all points over the heater
face (see Figure 1).
4. The air must be filtered. The incoming air
must be free from all debris, combustible
particles, and hazardous vapors.
5. Locate the heater at least 24 in. from an
elbow or turn (see Figure 2).
6. Locate the heater at least 48 in. from the
following (see Figures 3-7):
• heat pump or central air
• canvas duct connector or transition
section for change in duct size.
• downstream from an air handler.
• upstream from a humidifier
• downstream from an air filter
•
fan
500 fpm
470 fpm
780 fpm
EXAMPLE: IF 780 fpm IS REQUIRED
EXAMPLE: IF 780 fpm IS REQUIRED
EXAMPLE: IF 780 fpm IS REQUIRED
CORRECT
MIN. AIRFLOW AND EVEN AIR
DISTRIBUTION ARE PRESENT
INCORRECT
MIN. AIRFLOW AND EVEN AIR
DISTRIBUTION ARE NOT PRESENT
INCORRECT
MIN. AIRFLOW IS NOT PRESENT
FIG. 1
470 fpm
470 fpm
780 fpm
780 fpm
780 fpm
780 fpm
FIG. 2
FIG. 3
Heat Pump or Air Conditioner
24" MIN.
48" MIN.
HEAT PUMP OR
AIR CONDITIONER
HEATER
HEATER
DUCT
DUCT
FIG. 2
FIG. 3
Heat Pump or Air Conditioner
24" MIN.
48" MIN.
HEAT PUMP OR
AIR CONDITIONER
HEATER
HEATER
DUCT
DUCT
INCORRECT
CORRECT
FIG. 4
Transition Change
HEATER
48" MIN.
48" MIN.
HEATER
DUCT
DUCT
6