Connection To The Furnace; Balancing The Unit - Venmar 41502 User's And Installer's Manual

For the Installer

7. CONNECTION TO THE FURNACE

Never connect a 120-volt AC circuit to the terminals of the furnace interlock (standard wiring). Only use the low
voltage class 2 circuit of the furnace blower control.
F
OR A FURNACE CONNECTED TO A COOLING SYSTEM
On some older thermostats, energizing the "R" and "G" terminals at the furnace has the effect of energizing "Y" at the thermostat and
thereby turning on the cooling system. If you identify this type of thermostat, you must use the
STANDARD FURNACE INTERLOCK WIRING
W R G
FOUR
WIRES
TWO WIRES
heating only
W
R
G
C
Y
FURNACE
24-VOLT
TERMINAL BLOCK
VE0108A

8. BALANCING THE UNIT

P
REPARATION
Follow these steps to ensure accurate measurements:
• Seal all the ductwork with tape. Close all windows and doors.
• Turn off all exhaust devices such as range hood, dryer and bathroom fans.
• Make sure the balancing dampers are fully open by turning clockwise the thumb screw located on the Stale air to outdoors and Fresh
air from outdoors ports.
• If the installation is in any way connected to the ductwork of the cold air return of a furnace/air handler, make sure that the furnace/
air handler blower is ON. If not, leave furnace/air handler blower OFF.
• If the outside temperature is below 0°C/32°F, make sure the unit is not running in defrost while balancing by waiting 10 minutes after
plugging the unit in.
• Set the unit to high speed.
B P
ALANCING ROCEDURE
1. Place the magnehelic gauge on a level surface and adjust it to zero.
2. Connect tubing from gauge to EXHAUST airflow pressure taps (see diagram on unit door).
3. Be sure to connect the tubes to their appropriate high/low fittings. If the gauge drops below zero, reverse the tubing connections.
4. Note the CFM value from balancing chart on the unit.
5. Repeat steps 3 and 4, but to FRESH airflow pressure taps.
6. Using the appropriate adjustable balancing damper, lower the highest value so it matches the lowest value. A difference up to ±10 cfm
is acceptable.
7. Secure both dampers in place with a fastening screw (included in the hardware kit).
8. Write the required airflow information on a label and stick it near the unit for future reference (date, maximum speed air flows, your
name, phone number and business address).
:
THERMOSTAT
Y TERMINALS
TWO WIRES
COOLING SYSTEM
⚠
WARNING
ALTERNATE FURNACE INTERLOCK WIRING
W
4 WIRES
2 WIRES
heating only
W
R R
G
C
Y
Y
FURNACE
24-VOLT
TERMINAL BLOCK
12
ALTERNATE FURNACE INTERLOCK WIRING
THERMOSTAT
R G Y
TERMINAL
wiring
nuts
NO
NC
C
2 WIRES
.
COOLING SYSTEM