System Wiring - EWC Controls ULTRA-ZONE NCM-3z Technical Bulletin

System Wiring

WARNING:
T
he NCM-3z zone control is designed for use with 24vac only!
Use caution to avoid electric shock and/or equipment damage to this product or the HVAC system. All work
should be performed by a qualified technician, to National/Local codes and ordinances. Use 18awg solid
copper, color-coded, multi-conductor cable. Plenum rated where applicable. Shielded cable is not required.
Typical gas/electric system wiring for a
Single
Stage single stage furnace with AC. It's not
Gas/Electric
required but if you have enough wires.
System
connect the 24v "C" wire as shown below.
Single Stage
GAS/LP
Outdoor
Furnace
Condensing
1 STAGE
Unit
W
Y
Y
C
G
R
C
NOTE: You should connect the 'C' common
terminal from the HVAC system to the NCM-3z
"System" block, to make troubleshooting easier.
Figure 11
Typical gas/electric system wiring for a two
Two Stage
stage furnace with AC. The NCM-3z will
Gas/Electric
control W2 (high fire) not the Zone
System
thermostats.
GAS/LP
Single Stage Furnace
Outdoor 2 STAGE
Condensing
Unit
W2
W1
Y
Y1
C
G
R
C
NOTE: On a 2 stage furnace, W2 is controlled
by the NCM-3z Staging Timer (if enabled). If you
enable the Staging Timer, the default delay is 15
minutes. The adjustable range is 7 to 42 minutes.
Figure 12
EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-635-8646
NCM-3z
"SYSTEM"
Block
W2/E
W W1/B
O
Y
Y
G G
RH
R
RC
C
C
RC - RH RC - RH
LINKS LINKS
S1 - S2 S1 - S2
NCM-3z
"SYSTEM"
Block
W2
W2/E
W1 W1/B
O
Y1
Y
G G
RH
R
RC
C
C
RC - RH RC - RH
LINKS LINKS
S1 - S2 S1 - S2
Typical heat pump system wiring with electric
Heat Pump
resistance backup heat. Wire the HP reversing
with "O" type
valve to the "O" terminal on the system block.
Reversing Valve
logic
Read the "Important Note" below!
with 1 or 2 stage
"O" type
Electric Resistance
Single stage
Outdoor
Heat Pump
X / W
Y
O
R
C
NOTE: Auxiliary heat always connects to the W2/E terminal!
* *
When you program the NCM-3z for "O" type Heat Pump, the
W1/B function automatically changes to "B". (It is no longer W1)!
Do Not connect Auxiliary heat to W1/B, because it now
functions as "B", not "W1".
Connect your "O" reversing valve
wire to the "O" terminal, not the W1/B.
Auxiliary heat always connects to the W2/E terminal!
Figure 13
Typical heat pump system wiring with electric
Heat Pump
resistance backup heat. Wire the HP reversing
with "B" type
valve to the "W1/B" terminal on the system
Reversing Valve
block.
logic
Read the "Important Note" below!
with 1 or 2 stage
"B" type
Electric Resistance
Single stage
Outdoor
Heat Pump
X / W
Y
B
R
C
* * NOTE: Auxiliary heat always connects to the W2/E terminal!
When you program the NCM-3z for "B" type Heat Pump, the W1/B
function automatically changes to "B". (It is no longer W1)!
Connect your "B" reversing valve wire to W1/B terminal, not
the "O" terminal.
Auxiliary heat always connects to the W2/E terminal!
Figure 14
Do not use other voltages!
AIR HANDLER
NCM-3z
"SYSTEM"
Auxiliary Heat
W1 W1
W2
W2
* *
Y Y
O
O
G
G
R
R
C
C
RC - RH RC - RH
S1 - S2 S1 - S2
AIR HANDLER
NCM-3z
"SYSTEM"
Auxiliary Heat
W1 W1
W2
W2
Y Y
* *
B
B
G
G
R R
C
C
RC - RH RC - RH
S1 - S2 S1 - S2
E-Mail- info@ewccontrols.com
Block
W2/E
W1/B
O
Y
G
RH
RC
C
LINKS LINKS
Block
W2/E
W1/B
O
Y
G
RH
RC
C
LINKS LINKS
13