User Guide

4
The NCM300 panel was designed to be easy to understand
and wire up. We have provided several typical field wiring
diagrams to review. Your actual field wiring may vary. Notice
that you may now connect the 24vac “C” common terminal
from the HVAC system to the NCM300 “system” terminal
block. This provides a convenient place to reference the
HVAC system 24vac common wire and helps to simplify the
troubleshooting process.
Typical gas/electric system showing 1
or 2 stage heating. Note the jumper
(link) between RC and RH. There is
no need to install your own jumper.
System Wiring
Single
Transformer
Gas/Electric
Systems
Heat Pump
with O or B Type
Reversing Valve
Two
Transformer
Hydronic Heat
Systems
EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX [phone] E-Mail- [e-mail]
Figure 3a.
Figure 3c.
Figure 3b.
Figure 3d.
W2/E
W1/B
SYSTEM
RH
RC
O
Y
G
RC/RH
LINK
BOILER CONTROL
CIRCULATOR
RELAY OR HOT
WATER ZONE VALVE
CONNECTION
T
T
Y
C
Y
G
C
R
Y
G
C
R
TYPICAL Hydronic
Air Handler
TERMINAL
BLOCK
OUTDOOR
CONDENSING
UNIT
W
W
TT
OEM provided
ISOLATION
TERMINALS
OR WIRES
Note: Your Hydronic Air Handler may include a W terminal.
That means it may have it’s own isolation circuit. If you can
confirm this, simply connect the W1/B terminal to the W
terminal on the air handler. Do not cut the Rc/Rh Link. Wire
up your Boiler Control or Circulator Control to the isolation
contacts or wires provided in the air handler. (Follow dashed
lines)The fan is controlled via time delay relay inside the air
handler or use the Fan Hydro switch on the NCM300.
NCM300
Typical heat pump system wiring with electric
resistance backup heat. Wire up the reversing
valve to either O or W1/B, depending on your
type of system. Applies to air cooled or
geothermal / ground source HVAC systems.
AIR HANDLER
WITH 1 0R 2 STAGE
ELECTRIC RESISTANCE
BACKUP HEAT
HEAT PUMP
1 STAGE
NCM300
X / W
Oor B
Y
C
R
W2/E
W1/B
SYSTEM
RH
RC
O
Y
G
RC/RH
LINK
W2
W1
Y
G
C
R
W2
W1
Y
G
C
R
*
* Connect either the O or the W1/B.
In a typical O type reversing valve system, there
will not be a connection to the W1/B terminal!
W2/E
W1/B
SYSTEM
RH
RC
O
Y
G
RC/RH
LINK
NCM300
GAS/OIL
Furnace
1or2 STAGE
Y
C
OUTDOOR
CONDENSING
UNIT
G
Y1
W2
C
R
G
Y1
W2
C
R
W1
W1
C
C
C
NOTE: You may connect the ‘C’ common
terminal from the HVAC system to the NCM300
to make troubleshooting a little easier.
DO NOT cut
the Rc/Rh link
W2/E
W1/B
SYSTEM
RH
RC
O
Y
G
RC/RH
LINK
TYPICAL BOILER or
FURNACE
PRIMARY BURNER
CONTROL
Y
C
Y
G
C
R
Y
G
C
R
TYPICAL Fan Center
TERMINAL
BLOCK
OUTDOOR
CONDENSING
UNIT
NCM300
C
OIL
BURNER
PRIMARY
CONTROL
T
T
YOU MUST cut
the Rc/Rh link
Two
Transformer
Oil Heating
Systems
Your Oil furnace may not provide factory isolation for
the Primary Burner Control. Simply cut the Rc/Rh link
on the NCM300 and wire up to the Fan Center as
shown. Then run the T&T connections to the Rh and
the W1/B terminals to complete the control wiring.