EWC Controls ULTRA-ZONE NCM-3z Technical Bulletin page 7

LCD Screen Programming
FRESH AIR OPT N
On two zone applications, the spare Zone #3 may be
used to control a Fresh Air damper. The NCM-3z will
calculate "Minutes of Fresh Air per Hour" for you, based
on the variables you set, as described on this page.
Select N for NO, if you do not want or need this feature.
Select Y for YES to activate this feature and use Zone 3
to operate a Fresh Air (FA) damper.
NOTE: You must install a dedicated Outside Air
damper (24vac motorized) and route the OA duct to the
return air plenum of the HVAC system. Make sure the
Outside Air "passes through" the HVAC system's
primary air filter or provide a dedicated Outside Air filter.
NOTE: DO NOT locate the OA intake within 3 ft of any
appliance vent/exhaust or sewer vent pipe. Provide an
insect/rodent/bird screen on the outside air duct intake.
Follow local and/or national mechanical code.
NOTE: The "Minutes of Fresh Air/Hour" calculated by
the NCM-3z, does not credit for "other means" of Fresh
Air coming into the building such as an ERV/HRV, open
windows/doors or natural infiltration.
the "Minutes of FA/Hr" to your liking, if you disagree with
the FA cycle time calculated by the NCM-3z.
1800sqft
FA Area
If you selected Y for Yes on Step 13, this screen will
appear next in the menu.
Set the Square Footage of the home on this screen by
pressing the up or down buttons! Each press of the
button adjusts the square footage 100sqft at a time.
The adjustable range is 500sq ft to 5000 sq ft and the
default is 1800sq ft.
You may round up or down to get as close to the actual
square footage as you can.
EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-446-5362
Use the Left or Right button to navigate and select Menu Features. Use the Up & Down
buttons to change or adjust the options available in that feature. Select only the functions you
want or need. For future reference, place a check mark next to each selection in the
boxes below or write the selected value in the box. Your changes will take effect in real
time and the NCM-3z will remember your settings even after a power failure.
4 Button LCD
Programming
Step 13
You may reduce
Step 14
FA Occupants
If you selected Y for Yes in Step 13, this screen will appear
after step 14.
Set the total number of people living in (occupying) the
home on this screen. The default number of occupants is
4 people. The adjustable range is 2 to 12 people.
NOTE: Do not include persons who are staying in the
home for a short time period. ie weekend visitors.
NOTE: Pets are optional and may be included if desired.
FA Duct Size
If you selected Y for Yes in Step 13, this screen will appear
after step 15.
Select the size (diameter) of your Outside Air duct. Most
residential/light commercial OA duct is round "steel" duct.
The default diameter is 6" (6in). The adjustable range is
from 4" diameter up to 8" diameter.
NOTE: If your OA duct is rectangular, use a duct calculator to
determine the equivalent diameter and select that size. ie 9" x
6" duct = 8" diameter round duct.
NOTE: Larger diameter OA duct will result in fewer FA
minutes/hour, because the larger duct can move more air than
smaller diameter duct.
Once you have selected the parameters for Fresh Air
cycling, the NCM-3z will calculate the "Minutes of Fresh
Air/Hour" required, in order to properly ventilate your
home with outside air.
Example below is 35 minutes per hour.
FA Minutes/Hr 35
FORCE FRESH AIR
NOTE: The NCM-3z will always attempt to achieve the
required minutes of FA/Hr by opening the OA damper
during heating and cooling operations. This will reduce
the impact of introducing cold or hot air into the home.
If the NCM-3z does not detect a sufficient quantity of heat
or cool demands
(in a given hour)
damper, the NCM-3z will force a FA cycle (at the end of
the hour), to satisfy the number of FA minutes remaining.
E-Mail- info@ewccontrols.com
Step 15
04
Step 16
6in
FA CYCLE 60m / 35m
in which to open the FA
7