EWC Controls ULTRA-ZONE NCM-3z Technical Bulletin page 10

The NCM-3z has built-in Time Delay events
Built-In
Time Delay
Settings
To avoid redundant or
doubling of time delay
functions, it may be
best to disable each
* Purge Delay = 60, 90, 120, 150 or 180 seconds.
Thermostat's "short
cycle" delay.
* Supply Air Limit Delay = 4 minutes, Fixed.
The NCM-3z Time
* S1 / S2 Safety Delay = 4 minutes, Fixed.
Delays will protect the
HVAC system from
short cycling. * Opposing Demand Timer = 20 minutes, Fixed.
Upon initial power-up or after a power
Start-up
failure, the NCM-3z will not start or resume
Delay
operations for 3 minutes.
After all zones are satisfied, the NCM-3z
will not re-start the same mode of operation
(heating or cooling) for a minimum of 4
Short Cycle
Delay minutes. Note: The
Purge Delay runs concurrently (within) the
4 minute Short Cycle delay.
In the event opposing zone thermostat
demands occur (heat vs cool or cool vs
heat) and the NCM-3z terminates the
current mode of operation (heating or
Change-Over
cooling), a 5.5 minute delay must expire
Delay
before the NCM-3z will switch to the
opposite mode of system operation.
The
not run concurrently with the Change-Over
delay. These two delays run separately.
At the end of any cooling or heating
Purge
operation, the NCM-3z will hold the "last to
Delay
call" damper(s) in the open position (all
others remain closed) for the time you
select. 60, 90, 120, 150 or 180 seconds.
If the NCM-3z detects that supply air
temperature has exceeded the selected
Supply Air
supply air temperature limit, it will cycle the
Limit
HVAC system off-line.The NCM-3z will not
Delay
resume HVAC operations until the supply
air temperature has moderated and 4
minutes has expired.
A 20 minute delay (
Opposing
function
Demand
must satisfy, before the NCM-3z will honor
Timer
a zone demand to "changeover" to the
opposite mode of system operation.
If the S1/S2 circuit opens, the NCM-3z will
S1 / S2
stop all Heating & Cooling operations.
Safety
When the S1/S2 circuit closes again, the
Delay
NCM-3z will resume Heating & Cooling
operations in 4 minutes.
10
EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-446-5362
to insure safe HVAC system operation!
* Start-up Delay = 3 minutes, Fixed.
* Short Cycle Delay = 4 minutes, Fixed.
* Changeover Delay = 4 minutes, Fixed.
Time Delay Definitions
(default)
90 second Purge Delay does
(default)
See page 5.
starts on every Heat/Cool
) must expire, or the active zone(s)
See page 6 & 10.
LINKS LINKS
S1 - S2 S1 - S2
* The S1/S2 jumper link
monitor a safety device. If the S1/S2 link is not cut, the NCM-3z
cannot detect when the safety device opens the circuit.
* The safety device must have normally closed (fail open) dry contacts!
* NOTE: If S1/S2 link is cut by accident, place a jumper wire across S1/S2 terminals.
Condensate Pump
Safety Float Switch
Connect the overflow safety circuit of your condensate pump to the S1/S2
terminals of the NCM-3z. So long as the float switch contacts remain closed,
90 second
the NCM-3z will operate the HVAC system. If the contacts open, the NCM-3z
will open all dampers and run the fan. NOTE: The S1/S2 link must be cut!
Red
NOTE:
Black
Connect 24vac and S1/S2 terminals to the Emergency "overflow" pan switch
as shown. So long as the emergency pan switch contacts remain closed, the
NCM-3z will operate the HVAC system. If the contacts open, the NCM-3z will
open all dampers and run the fan. NOTE: The S1/S2 link must be cut!
Ask the Fire Alarm Technician to connect your S1/S2 wires to a normally
closed (NC) "dry contact" in the Fire Alarm panel. Note: The Tech will not let
you connect them and if he does allow you, you should decline due to liability.
Confirm with the Technician that the dry contact will "OPEN" when the Fire
Alarm system goes into "Alarm Mode". Test the circuit and confirm that the
NCM-3z shuts down the HVAC system, including the Fan. All directly
connected zone dampers should stroke to the "closed" position, to reduce
smoke migration. The NCM-3z will not resume HVAC operations until the Fire
Alarm panel is reset, and the S1/S2 circuit closes.
dampers are not fire/smoke rated. No claims/guarantees of such are made herein.
S1/S2 Safety Circuit Details
(at bottom left corner)
S1 & S2 "Purges"
Setting
water water
Green
Orange
Insulate the
unused wire!
White
Diversitech®
S1 & S2 "Purges"
WS-1
FIRE ALARM
SYSTEM
The S1/S2 link
NC C NO
must be cut!
E-Mail- info@ewccontrols.com
must be cut in order to
Figure 3 Figure 3
R
C
S1
S2
Figure 4 Figure 4
R
C
S1
S2
Setting
Figure 5 Figure 5
S1 & S2 "Stops"
Setting
R
C
S1
S2
Warning: Residential zone