Controls; General Information; Sequence Of Operation; Defrost - Venmar 6LC Installation, Operation And Service Instructions

3.1 General Information

F I R O
AN NTERLOCK ELAY UTPUT
External fan control can be achieved by connecting an external 24 volts fan control through dry contacts (FF). These contacts are closed
on a call for ventilation or defrost. See wiring diagram shown in Appendix E.
S S (6LC, V6LC /12LC, V12LC
PEED ELECTION
There are three speed settings available with the controls, only two of which can be functional at any one time. The units are factory set
to use the low and high speed taps on the blower motors. If necessary, the medium speed tap can be used instead of the low speed tap.
See wiring diagrams for instructions on how to make this change. Units without the remote wall control option can be shut off by opening
the contact between LOW - COM or HIGH - COM as shown in Appendix E-2.

3.2 Sequence of Operation

Before start-up, check the unit for obstructive packaging, objects near or in blowers, dampers, heat exchangers, etc. Once installation
is complete, check all modes of operation to ensure that the unit is working properly. Close the doors and check for operation on LOW,
COM and HIGH. Use a wall control or the dry contact switching to run fan speeds as shown in Appendix E-2.
The 7000 unit is two speed. Low speed can be initiated by creating a closure across LOW - COM or high speed can be initiated by creating
a closure across HIGH - COM.
U C (
NIT HECK POINTS ALL UNITS
• Power connected, no ventilation call - Both fans are off, defrost damper (if equipped) closes off fresh air from outdoors.
• Power connected, low speed call - Both fans on low speed internal defrost damper (if equipped) opens fresh air from outdoors. For 6LC,
V6LC, 12LC and V12LC units only, if equipped with recirculation module, the internal defrost damper closes recirculation opening.
• Power connected, high speed call - Both fans on high speed, defrost damper opens fresh air from outside. For 6LC, V6LC, 12LC and
V12LC units only, if equipped with recirculation module, the internal defrost damper closes recirculation opening.
• Power connected, occupied timer/sensor connection open (unoccupied mode) - Both fans are off, defrost damper closes fresh air
from outdoors. For 6LC, V6LC, 12LC and V12LC units only, if equipped with recirculation module, the internal defrost damper opens
recirculation opening.
• Power connected, FF control contacts close during unit ventilation or defrost cycle.

3.3 Defrost

The unit functions are controlled by integrated controls in the unit which may include Exhaust Only Defrost or Recirculation Defrost (via
the recirculation module - 6LC, V6LC, 12LC and V12LC units only). In cold temperatures, defrost cycles will remove frost from the heat
recovery core to maintain good operation.
E O D (O
XHAUST NLY EFROST PTIONAL
Frost removal occurs when the supply blower de-energizes, the supply air damper and the core damper close and the exhaust fan
continues to circulate only warm inside air through the heat recovery core or energy recovery core to maintain ventilation. This process
prevents the build up of ice in the core. Defrost is temperature initiated at 23°F to -22°F (-5°C to -30°C) and time based.
A negative building pressure may develop during the defrost cycle with possible back drafting fumes from
combustion equipment, which may have severe health consequences.
R D M
ECIRCULATION EFROST ODULE
The Recirculation Defrost Module is only available with the 6LC, V6LC, 12LC and V12LC units. The defrost cycle is electronically controlled
in response to the outdoors temperature 23°F to -22°F (-5°C to -30°C).On a call for defrost, the supply air damper in the recirculation
module closes, exhaust fan is de-energized and the supply fan continues to recirculate warm air through the heat recovery core or energy
recovery core. It is possible to extend the defrost times during very cold weather by removing the jumper JU1-F on the circuit board as
shown in Appendix F. For dimension and weight changes to the 6LC, V6LC, 12LC and V12LC models with recirculation defrost, see
Appendix B-2 and B-4.

3.4 Remote Wall Control (Optional)

Remote mounted wall control options can be used to control the ventilators from a location remote to the installed unit location. The
connection from the ventilator to the control is low voltage and requires a 4 conductor (24 ga. minimum) LVT cable. Models are available
with a dehumidistat control. The following two options are available.
S S T
LIDE WITCH YPE
Dehumidistat to engage high speed exchange. Slide switch operation supporting continuous low exchange and continuous high exchange.
P E T ( 7000
OOL LECTRONIC YPE FOR
Ideal for pool dehumidification. Dehumidistat to engage high speed exchange. Push-button operation supporting: intermittent (stand-by)
ventilation, continuous low exchange, continuous high exchange, maintenance indicator light and exchange indicator light.
(FF)
)
UNITS ONLY
):
)
(O - F I
PTIONAL ACTORY NSTALLED
)
UNIT ONLY

3. Controls

WARNING
!
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