rol
Panel
CONTROL
SYSTEM
K6
K7
R6
R7
C7
+
C6
+
D11
D12
D10
D6
D4
D9
D5
D3
D21
D22
D20
D19
D24
D23
D25
D26
C
W
Y
R
ZONE
2
T'STAT
C
W
Y
R
R1
0
B
G
ZONE
1
T'STAT
CAUTION
0
R
C
+
-
ADDITIONAL
ZONE
PANEL
#1:
WIRING
DIAGRAM
HEATING
ONLY
INSTALLATION
rol
Panel
K6
K7
R6
R7
C7
+
C6
+
D11
D12
D10
D6
D4
D9
D5
D3
D21
D22
D20
D19
D24
D23
D25
D26
C
W
Y
R
ZONE
2
T'STAT
C
W
Y
R
R1
0
B
G
ZONE
1
T'STAT
CAUTION
0
R
C
+
-
ADDITIONAL
ZONE
PANEL
#2:
WIRING
DIAGRAM
COOLING
ONLY
INSTALLATION
AP PL ICA TIO N
NO TES
OPERATION
To operate the system in the heat mode,
the "B" terminal has to be made to the "R1"
terminal on the zone 1 terminal block.
This
allows any zone thermostat to call for heat.
When a zone calls for heat, the control
panel closes
the circuit
from "R" to "W"
activating the furnace.
The zone damper
calling for heat remains open and zones
satisfied will close. The fan and limit control
in the furnace will operate the fan.
1.
HEAT
MODE:
2.
COOL
MODE:
To operate the system in the cool mode,
the "O" terminal has to be made to the "R1"
terminal on the zone 1 terminal block.
This
allows for any thermostat to call for cooling.
On call for cooling, terminals "R", "G" and
"Y" are made
to
bring
on
the fan and
compressor.
The dampers for zones calling
will remain open; the dampers satisfied will
close.
3.
OFF POSITION:
When the subbase on zone 1 is in the
"OFF" position the entire system is disabled.
4.
CONTINUOUS
FAN:
When
placing
the
fan
switch
on
the
subbase from "AUTO" to "ON" position, the
panel closes the circuit between "R" and "G"
terminals to energize the fan relay.
5.
OPEN-CLOSE SWITCHES:
If left in the open position when all zones
satisfy,
the
damper
will
drive
to
open
position.
If left in closed position, when all
zones
satisfy
,
the
damper
will
remain
closed unless it is the last zone to satisfy;
then it will remain open.
NOTE: The last zone to satisfy will always
be open regardless of position of switch.
WIRING
1.
HVAC SYSTEM:
Wiring the HVAC system to the EWC-ST-2E
or EWC-ST-3E is typical of wiring a subbase
to
a
heating/cooling
system.
(4
wires
required.)
The following terminals are on the system
terminal block:
R-
Y-
W-
G-
Wire
to
the
RH
heating
transformer
and/or the RC cooling transformer.
Wire to the Compressor Relay.
Wire
to
Heat
Control
(gas
valve,
oil
burner relay) on system terminal block.
Wire to Fan Relay.
2.
TRANSFORMER 24V 40VA:
A separate 24V 40VA transformer is required
to be wired to terminals 1 and 2 of the
terminal block labeled "T-Former".
(2 wires
required.) This transformer powers the panel
board, thermostats and damper motors.
It
does
not
power
the
furnace
or
the
air
conditioner.
The board is now protected by
a
Thermal Polyfuse
at the transformer input.
When the polyfuse trips it will get quite hot. To
reset the breaker, remove the 24 VAC for
approximately 30 seconds. Check the damper
motors and field wiring for shorts. If adding two
panels together, be sure of wiring in (+ and - )
circuit.
3.
ZONE DAMPER MOTORS:
Use 3 conductor wire from each set of MAN
or
RDN
zone
damper
terminals
or
2
conductor
wire on
"SR" dampers
to
the
panel. See diagrams #4 and 5 when wiring
more than one damper per zone.
ZONE 1: Thermostats that have subbases
with "B" and "O" terminals are required to
enable system changeover.
These include
mechanical
and
battery
operated
thermostats (6 wires required - terminals W,
Y, G, R, B and O), and electro-mechanical
and programmable
digital thermostats (24
VAC, 7 wires required - terminals C, W, Y,
G, R, B and O).
If model MCS-DXB remote selector switch is
used, it will be wired to the zone 1 terminal
block in place of the changeover subbase
(7 wires required total: 4 on the MCS-DXB -
B, G, O and R1; 3 on the thermostat - W,
Y and R). See diagram #3.
OTHER ZONES: 3 wires are required for
mechanical
and
battery
operated
thermostats - terminals W, Y and R. 4 wires
are required for electro-mechanical and 24
VAC digital thermostats - terminals C, W, Y
and R. No subbases required.
See
page
6
for
specific
types
of
thermostats required.
4.
THERMOSTATS:
5.
HEAT
ONLY OR
COOL
ONLY
Zone 1 no longer requires a subbase or
remote switch.
All zones need only a two
or three wire thermostat to operate in either
heat or cool.
APPLICATIONS:
2
CONTROL
SYSTEM
EWC Controls Inc.
•
385 Highway 33
•
Englishtown, NJ
07726 •
800-446-3110
•
FAX 732-446-5362
R
G
Y
W
O
B
ZONE 2 THERMOSTAT
R
G
Y
W
O
B
ZONE 1 THERMOSTAT
FIELD
INSTALLED
JUMPER
R
G
Y
W
O
B
ZONE 2 THERMOSTAT
R
G
Y
W
O
B
ZONE 1 THERMOSTAT
FIELD
INSTALLED
JUMPER
