3
Make sure the temperature and humidity sensors are installed into the 6” insulated fresh
air duct between the wall cap and MD6 motorized damper if necessary.
5.
DUCTING
All ducting and fresh air intake construction/location must comply with local and national building
codes. Do not locate fresh air intakes near contaminant sources (ex: dryer exhaust vent, garbage,
etc). Connect the ductwork to the wall cap and HVAC return duct with screws, cable ties, worm clamps,
and rated tape as necessary. Ensure that the ductwork is properly connected to a properly sized, low
restriction fresh air intake with weather hood and insect screen.
S&P recommends round 6” insulated rigid ductwork for best air and sound performance. Round 6”
flexible ductwork is acceptable, but ensure that it is pulled tight to reduce losses. Keep the length of
duct and number of elbows to a minimum for best air and sound performance. Insulated ductwork
will minimize building heat loss/gain and reduce the potential for condensation.
The ducting from the HVAC unit fan to the outside of the building has a strong effect on the air flow, noise
and energy use of the fan. Use the shortest, straightest duct routing possible for best performance, and
avoid installing smaller ducts than recommended. Insulation around the ducts can reduce energy loss
and inhibit mold growth.
Ductwork connections and penetrations should be sealed with duct tape, duct fast-clamps, or caulk
(available through your local distributor) to create an air-tight path from the building exterior to the
ventilated space.
6. WIRING
CAUTION:
Ensure that power is turned off and locked out before making any wiring connections.
The MD6-ES24VK operates from a standard 24V 60Hz AC electrical supply. There are multiple
wiring scenarios available depending on the installer preferences. The diagrams below show 3
common scenarios where the ES24V is connected either directly to the HVAC unit transformer or an
auxiliary transformer and the MD6 is connected either directly to the ES24V damper terminals or to
the ES24V damper terminals through a SPST, N.O. 24V relay and transformer. This will depend on
the VA available from the HVAC unit transformer. S&P recommends 20VA be available to operate
the MD6 motorized damper. If 20VA is not available from the HVAC unit transformer, then an
auxiliary transformer to power the ES24V and MD6 is recommended (transformers and relays provided
by others).
All wiring must be carried out by a qualified electrician in accordance with National Electrical Code and
all applicable state and local buildings codes. Electrical connections should be made in accordance
with the following
Figures: 1-3
