EWC Controls ULTRA-ZONE ST2E Series Service manual

CONTROLS INC.
Excellence Without Compromise
WARNING: THESE PANELS ARE DESIGNED
FOR USE WITH 24 VOLTS. DO NOT USE
ANY OTHER VOLTAGE! USE CAUTION TO
AVOID ELECTRIC SHOCK OR EQUIPMENT
SPECIFICATIONS
Power Requirements: 24V 60Hz 40VA
Wiring Connections: Screw Terminal blocks
for Thermostat gauge wire connections.
Mounting: Mounts with 4 screws and
mollies (included).
Panel Dimensions: Length: 10” (254mm);
Width: 9 7/8" (251mm); Depth: 1 9/16” (40mm).
TABLE OF CONTENTS
PAGE
1
2
5
6
7
8
Introduction & Specifications
Application Notes
Typical 5 zone control panel diagram
Thermostat Requirements (See Notes)
Checkout Procedures
EWC-ST-3E Wiring Diagram
EWC-ST-2E
Models EWC-ST-2E & EWC-ST-3E
T E C H N I C A L B U L L E T I N
Model EWC-ST-2E ZONE2
T’STAT
ZONE1
T’STAT
C
W
Y
R
C
W
Y
R
R1
O
B
G
O
R
C
+
_
ADDITIONAL
ZONE PANEL
CAUTION
PLEASE read all
instructions carefully
before starting the
installation
procedures.
J1
SYSTEM
24VAC
T’FORMER
2
1
ZONE2
MOTOR
ZONE1
MOTOR
M6
M4
M2
M1
M6
M4
M2
M1
SW1
SW2
OPEN
CLOSE
OPEN
CLOSE
EWC
CONTROLS INC.
Englishtown, NJ
ULTRA-ZONE
CONTROL SYSTEM
Y
W
G
R
B
O
X
CB1
Congratulations on purchasing the ST2E/ST3E series
ULTRA-ZONE Control Panel. The ST series of zone control
panels are still the same popular, field proven zone control
panels that have been in use for the last seventeen years! The
new “E” series revision has a few upgrades to enhance the
reliability, protection and operation of the board.
First and most important is the replacement of the old 3 amp
slo-blo fuse, with an integrated Thermal Circuit breaker or
Polyfuse. This means no more running to the electronics store
to buy a fuse, after the spare fuse that was provided has blown.
The Polyfuse protects the panel against shorts in the thermostat
or damper field wiring. It does not protect against shorts in the
HVAC equipment field wiring. See page 2.
The location of the J1 jumper on the panel has also changed, and
there is now an arrow pointing to it. The J1 jumper enables
fan operation in Heat mode as well as Cooling mode.
With the exception of the Polyfuse and the J1 jumper, all
other changes have no direct bearing on the wiring,
installation, or operation of the control panel.
The ST series zone control panels are the most versatile
and rugged relay based logic control systems in use today.
The Master/Slave circuitry of these panels can be utilized
to satisfy numerous control applications and job specifications.
The heating/cooling changeover operation is still controlled by a
changeover subbase on the zone 1 thermostat, or a separate
remote selector switch can be used instead. This allows
for inexpensive standard 2 or 3 wire thermostats to be used in all
zones depending on the field application.
The table on Page 6 shows the types of digital programmable
thermostats that are compatible with the ST2E or ST3E panels.
The diagrams included with this bulletin are based upon the
most frequently asked questions regarding the wiring of these
panels. There are additional diagrams available through the
Technical Support Hotline@ 1-800-526-4048.
Contact the Hotline if you find yourself on the job site and
unsure of the exact wiring for your ST Series Control Panel.
DAMAGE
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ewccontrols.com/acrobat/090375a0248.pdf
TB-115
P/N 090375A0115 REV. N 11.5.20
EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX [phone] E-Mail- [email protected] 1
Copyright ©2009 EWC Controls All Rights Reserved

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
aThermal 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 [phone]
R
GYW
OB
ZONE 2 THERMOSTAT
R
GYW
OB
ZONE 1 THERMOSTAT
FIELD
INSTALLED
JUMPER
R
GYW
OB
ZONE 2 THERMOSTAT
R
GYW
OB
ZONE 1 THERMOSTAT
FIELD
INSTALLED
JUMPER

Panel
K6
K7
C
W
Y
R
ZONE 2
T'STAT
C
W
Y
R
R1
0
B
G
ZONE 1
T'STAT
CAUTION
0
R
C
+
-
PLEASE read all
instructions carefully
before starting the
installation procedures.
ADDITIONAL
ZONE PANEL
CONTROL SYSTEM
GREEN
BROWN
RED
ORANGE
RED
HEAT
OFF
COOL
FAN
ON AUTO
Front of Plate
Back of Plate
#4: TYPICAL TANDEM
DAMPER WIRING
3
#3: EWC-ST-2E WITH MCS-DXB
REMOTE SELECTOR SWITCH
#5: CONTROL OF UP TO FOUR DAMPERS PER ZONE
USING EXTERNAL RELAY
K9
K8
X
R
G
W
Y
B
O
1
2
K4
SW1
24V
T'FORMER
K2
K1
K5
OPEN
CLOSE
OPEN
CLOSE
SW2
M1
M2
M4
M6
ZONE2
M1
M2
M4
M6
ZONE1
MOTOR
MOTOR
Model
CONTROLS
Englishtown
MA-ND4 TYPE MOTORS ON
ND OR URD TYPE DAMPERS
EWC Controls Inc. • 385 Highway 33 • Englishtown, NJ 07726 • 800-446-3110 • FAX [phone]
CB1
RED
RED
BROWN
ORANGE
GREEN
1
6
4
1
6
4
1
6
4
1
6
4
24VAC TRANSFORMER
40 - 60VA RATING
MAX. NUMBER OF 4 DAMPERS
PER ZONE.
Multiple Damper Wiring on a Single Zone, using a Separate Transformer
and an Isolating Relay. Maximum of 4 dampers per 40 va transformer.
M1
M2
M4
M6
ZONE
MOTOR
46
1
46
1
46
1
2
1
3
COIL
24 vac
NC
NO
C
R1 Isolation Relay
SPDT action with 24 vac coil
Relay is shown de-energized.
All dampers are closed.
To Line Voltage
Provide over current
protection
46
1
Separate 24 vac
Transformer
TYPICAL FEEDER CONDUCTOR
TYPICAL JUNCTION POINT
L1
L2
H
C
One relay coil=One motor.
Don’t overload your power
transformer, by connecting
too many relays.
R
GYW
OB
ZONE 2 THERMOSTAT
R
GYW
OB
ZONE 1 THERMOSTAT

#6: TYPICAL FAN CENTER AND OIL
BURNER WITH ISOLATION RELAY #7: TYPICAL GAS FURNACE
#8: FAN CONTROL
WITH HOT WATER COIL
#9: ZONING IN HEATING ONLY
NO ZONE CONTROLLED COOLING
4
LAY
RELAY
T
T
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
+
-
PLEASE read all
instructions carefully
before starting the
installation procedures.
ADDITIONAL
ZONE PANEL
K9
K8
X
R
G
W
Y
B
O
1
2
K4
SW1
24V
T'FORMER
K2
K1
K5
OPEN
CLOSE
OPEN
CLOSE
SW2
M1
M2
M4
M6
ZONE2
M1
M2
M4
M6
ZONE1
MOTOR
MOTOR
Model
CONTROLS
Englishtown
K9
K8
X
R
G
W
Y
B
O
1
2
K4
SW1
24V
T'FORMER
K2
K1
K5
OPEN
CLOSE
OPEN
CLOSE
SW2
M1
M2
M4
M6
ZONE2
M1
M2
M4
M6
ZONE1
MOTOR
MOTOR
Model
CONTROLS
Englishtown
K9
K8
X
R
G
W
Y
B
O
1
2
K4
SW1
24V
T'FORMER
K2
K1
K5
OPEN
CLOSE
OPEN
CLOSE
SW2
M1
M2
M4
M6
ZONE2
M1
M2
M4
M6
ZONE1
MOTOR
MOTOR
Model
CONTROLS
Englishtown
EWC Controls Inc. • 385 Highway 33 • Englishtown, NJ 07726 • 800-446-3110 • FAX [phone]
CB1
CB1
CB1
ISOLATION RE
HEATING
Y
C
Y
C
W
C
Y
R
G
Y
C
C
Y
R
G
RELAY
T
T
ISOLATION
RELAY
HEATING
Y
C
Y
C
C
Y
R
G
JUMPERS
CUT
**CUT ‘J1’ JUMPER**
FAN
CENTER
OUTDOOR
CONDENSING
UNIT
GAS
FURNACE
OUTDOOR
CONDENSING
UNIT
OUTDOOR
CONDENSING
UNIT
AIR
HANDLER
R
GYW
OB
ZONE 2 THERMOSTAT
R
GYW
OB
ZONE 1 THERMOSTAT
FIELD
INSTALLED
JUMPER

5
#10: WIRING DIAGRAM
INTERCONNECTION OF TWO PANELS FOR ADDITIONAL ZONES
MASTER PANEL
SLAVE PANEL
PANELS MAY BE
DAMAGED IF NOT
WIRED EXACTLY
AS SHOWN
0 to 0
R to R
C to C
+ to +
- to -
K9
K8
C9
C8
Z9
Z8
D19
D20
D21
D22
D26
D25
D24
D23
Z7
C6
C7
D17
D18
D12
D11
D10
D9
D3
D4
D5
D6
D13
D14
D15
D16
Z6
K3
K5
K4
K2
K1
K6
K7
C3
C2
C1
C5
C4
Z5
Z4
Z2
Z1
Z3
D8
D7
D1
D2
SW2
SW1
Y
W
R
C
ZONE-3
C
C
R
R
W
W
Y
Y
ZONE-2
ZONE-1
OPEN
OPEN
CLOSE
CLOSE
OPEN
CLOSE
M1
M2
M4
M6
ZONE3
M1
M1
M2
M2
M4
M4
M6
M6
ZONE2
ZONE1
T'STAT
T'STAT
T'STAT
MOTOR
MOTOR
MOTOR
-
+
R
O
C
G
B
O
R1
X
R
G
W
Y
B
O
1
2
24V
T'FORMER
Model EWC-ST-3E
CONTROL SYSTEM
CONTROLS INC.
Englishtown, NJ
CAUTION
PLEASE read all
instructions
carefully before
starting the
installation
procedures.
ADDITIONAL
ZONE PANEL
EWC Controls Inc. • 385 Highway 33 • Englishtown, NJ 07726 • 800-446-3110 • FAX [phone]
CB1
K9
K8
C9
C8
Z9
Z8
D19
D20
D21
D22
D26
D25
D24
D23
Z7
C6
C7
D12
D11
D10
D9
D3
D4
D5
D6
Z6
K5
K4
K2
K1
K6
K7
C2
C1
C5
C4
Z5
Z4
Z2
Z1
D8
D7
D1
D2
SW2
SW1
C
C
R
R
W
W
Y
Y
ZONE-2
ZONE-1
OPEN
OPEN
CLOSE
CLOSE
M1
M1
M2
M2
M4
M4
M6
M6
ZONE2
ZONE1
T'STAT
T'STAT
MOTOR
MOTOR
-
+
R
O
C
G
B
O
R1
X
R
G
W
Y
B
O
1
2
24V
T'FORMER
CONTROL SYSTEM
CONTROLS INC.
Englishtown, NJ
CAUTION
PLEASE read all
instructions
carefully before
starting the
installation
procedures.
ADDITIONAL
ZONE PANEL
CB1
Model EWC-ST-2E
1
6
4
1
6
4
1
6
4
1
6
4
1
6
4
DAMPER MOTORS
DAMPER MOTORS
TRANSFORMER
C
Y
G
Y
W
C
R
HVAC
EQUIPMENT
R
GYW
OB
ZONE 3 THERMOSTAT
R
GYW
OB
ZONE 2 THERMOSTAT
R
GYW
OB
ZONE 1 THERMOSTAT
R
GYW
OB
ZONE 5 THERMOSTAT
R
GYW
OB
ZONE 4 THERMOSTAT
PANELS MAY BE
DAMAGED IF NOT
WIRED EXACTLY
AS SHOWN

6
THERMOSTAT REQUIREMENTS
K6
K7
R6
R7
C7 +
C6 +
D11
D12
D10
D6
D4
D9
D5
D3
D21
D22
D20
D19
C
W
Y
R
ZONE 2
T'STAT
C
W
Y
R
R1
0
B
G
ZONE 1
T'STAT
CAUTION
EWC Controls Inc. • 385 Highway 33 • Englishtown, NJ 07726 • 800-446-3110 • FAX [phone]
ZONE 1
C
R
BY
W/E
ZONE 1 THERMOSTAT – MODEL EWT-725
G
W2
O
C
RC
BYW
ZONE 2 THERMOSTAT – MODEL EWT-601-2
G
RH
O
If the application is heat only, cool only or using the MCS-DXB
remote system selector switch, all thermostats must be set
to the same mode of operation at all times.
Zone 2 and Zone 3 thermostats must be in the same mode
(Heat or Cool) as the Zone 1 thermostat.
3
The Zone 1 (Master) thermostat must be set to heat or cool mode,
in order for Zone 2 or Zone 3 to function! If Zone 1 is turned “OFF”
Zone 2 and Zone 3 cannot function.
6 WIRES REQUIRED
MANUFACTURER
DIGITAL NON-
PROGRAMMABLE
THERMOSTATS
(Battery Operated)
DIGITAL
PROGRAMMABLE
THERMOSTATS
(Battery Operated)
EWT-725
Not Available
Not Available
EWC
CONTROLS
EMERSON
HONEYWELL Not Available Not Available
EWT-601-2
ZONES 2 & HIGHER
3WIRES REQUIRED
DIGITAL NON-
PROGRAMMABLE
THERMOSTATS
(Battery Operated)
DIGITAL
PROGRAMMABLE
THERMOSTATS
(Battery Operated)
EWT-725
EWC
CONTROLS
EMERSON
HONEYWELL Not Available Not Available
EWT-601-2
MANUFACTURER
WiFi
Thermostats
(Hardwired)
Not Available
Not Available
Not Available
NOTES
Not Available Not Available
4Manufacturers have been phasing out thermostat designs with
separate O & B terminals for many years now. Thermostats that are
compatible with the ST series controller are increasingly difficult
to find. As a result, the ST series zone control will soon phase out
as well. We suggest upgrading to our model NCM300 zone control,
which is compatible with 99% of the thermostats available
in today’s market. Including popular WiFi thermostats.

7
#12: SYSTEM CIRCUIT
#11: THERMOSTAT CIRCUIT
CH ECK OU T PROCEDUR E
#13: DAMPER CIRCUIT
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
+
-
PLEASE read all
instructions carefully
before starting the
installation
procedures.
ADDITIONAL
ZONE PANEL
D15
D16
D18
D17
C
W
Y
R
ZONE 3
T'STAT
HEATING MODE OFF MODE COOLING MODE
STAT
DAMPER
CALLING
OPEN
NOT CALLING
CLOSED
24 VOLTS
24 VOLTS
COMMON COMMON
O VOLTS
O VOLTS
O VOLTS
O VOLTS
O VOLTS
24 VOLTS
24 VOLTS
24 VOLTS
24 VOLTS
24 VOLTS
INPUT TO PANEL:
COMMON
24 VOLTS
NOTE: Conditions shown are with at
least one thermostat always calling.
When all thermostats satisfy, damper
position will depend on position of
"OPEN-CLOSED" switch. In "OPEN"
position, damper will drive to open
position. In "CLOSED" position, all
voltage is removed from damper motor;
motor will remain in whatever position it
was in when all thermostats satisfied.
If 24 volts is present from M1 to M4 and
M1 to M6, damper motor may either be
turning or stuck between open and
closed postions.
EWC Controls Inc. • 385 Highway 33 • Englishtown, NJ 07726 • 800-446-3110 • FAX [phone]
K9
K8
K3
K5
K4
K2
K1
SW2
SW1
OPEN
OPEN
CLOSE
CLOSE
OPEN
CLOSE
M1
M2
M4
M6
ZONE3
M1
M1
M2
M2
M4
M4
M6
M6
ZONE2
ZONE1
MOTOR
MOTOR
MOTOR
X
R
G
W
Y
B
O
1
2
24V
T'FORMER
EWC-ST-3E
CONTROLS
Englishtown
K9
K8
K3
K5
K4
K2
K1
SW2
SW1
OPEN
OPEN
CLOSE
CLOSE
OPEN
CLOSE
M1
M2
M4
M6
ZONE3
M1
M1
M2
M2
M4
M4
M6
M6
ZONE2
ZONE1
MOTOR
MOTOR
MOTOR
X
R
G
W
Y
B
O
1
2
24V
T'FORMER
EWC-ST-3E
CONTROLS
Englishtown
O VOLTS 24 VOLTS
COMMON COMMON
24 VOLTS 24 VOLTS
COMMON COMMON
24 VOLTS 24 VOLTS
CB1
CB1

8
#14: WIRING DIAGRAM
MODEL EWC-ST-3E CONTROL PANEL
CONTROLS INC.
Excellence Without Compromise Technical . . . . . . . 800-446-3110
Sales . . . . . . . . 800-446-3110
Fax . . . . . . . . .
EWC Controls Inc. • 385 Highway 33 • Englishtown, NJ 07726 • 800-446-3110 • FAX [phone]
K9
K8
C9
C8
Z9
Z8
D19
D20
D21
D22
D26
D25
D24
D23
Z7
C6
C7
D17
D18
D12
D11
D10
D9
D3
D4
D5
D6
D13
D14
D15
D16
Z6
K3
K5
K4
K2
K1
K6
K7
C3
C2
C1
C5
C4
Z5
Z4
Z2
Z1
Z3
D8
D7
D1
D2
SW2
SW1
Y
W
R
C
ZONE-3
C
C
R
R
W
W
Y
Y
ZONE-2
ZONE-1
OPEN
OPEN
CLOSE
CLOSE
OPEN
CLOSE
M1
M2
M4
M6
ZONE3
M1
M1
M2
M2
M4
M4
M6
M6
ZONE2
ZONE1
T'STAT
T'STAT
T'STAT
MOTOR
MOTOR
MOTOR
-
+
R
O
C
G
B
O
R1
X
R
G
W
Y
B
O
1
2
24V
T'FORMER
Model EWC-ST-3E
CONTROL SYSTEM
CONTROLS INC.
Englishtown, NJ
CAUTION
ADDITIONAL
ZONE PANEL
CB1
732-446-5362
1
6
4
DAMPER MOTORS
1
6
4
1
6
4
24VAC
TRANSFORMER
C
Y
HVAC
EQUIPMENT
G
Y
W
C
R
C
RC
BYW
ZONE 2 THERMOSTAT – MODEL EWT-601-2
G
RH
O
C
RC
BYW
ZONE 3 THERMOSTAT – MODEL EWT-601-2
G
RH
O
C
R
BY
W/E
ZONE 1 THERMOSTAT – MODEL EWT-725
G
W2
O