EWC Controls ULTRA-ZONE ST2E Series - User 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
(DISPONIBLE EN ESPAÑOL EN EWCCONTROLS.COM)
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 732-446-5362 E-Mail- info@ewccontrols.com
1
Copyright © 2009 EWC Controls All Rights Reserved

EWC Controls ULTRA-ZONE ST2E Series Specifications

General

Category	Control Panel
Model Series	ULTRA-ZONE ST2E Series
Transformer	40VA
Voltage Input	24 VAC
LED Status Indicators	Yes
Enclosure Type	Metal
Mounting	Wall mount
Weight	2 lbs
Stages	2
Zones	2
Number of Zones Supported	2
Maximum Load per Zone	1 Amp
Compatible Thermostats	Standard 24V

Summary

Product Specifications

Power Requirements

Details the power input voltage, frequency, and VA rating for the control panel.

Wiring Connections

Describes the type of terminal blocks used for connecting thermostat wires.

Mounting Method

Explains how the panel is mounted, including the type of hardware provided.

Panel Dimensions

Provides the physical length, width, and depth of the control panel unit.

Voltage Warning

Crucial safety warning about using only 24 volts to avoid damage or shock.

System Operation Modes

Heat Mode Operation

Explains how the system functions when a thermostat calls for heat.

Cool Mode Operation

Details the system's behavior and damper control during cooling calls.

Off Position Functionality

Describes what happens when the primary zone thermostat is set to OFF.

Continuous Fan Operation

How to enable the fan to run continuously using the subbase switch.

Open-Close Switch Behavior

Explains the function of open/close switches for zone dampers.

Wiring the HVAC System

HVAC System Connections

Details terminal connections for the main HVAC system components like R, W, Y, G.

Transformer Wiring

Instructions for wiring the required 24V 40VA transformer to the panel.

Zone Damper Motor Wiring

Guidance on wiring zone damper motors using 3-conductor wire.

Thermostat Wiring Requirements

Specifies wiring for Zone 1 and other zones, including subbase needs.

Heat;Cool Only Applications

How to wire the system for applications that are heat or cool only.

Application Notes

Heating Only Wiring Diagram

Illustrates the wiring configuration for heating-only installations.

Cooling Only Wiring Diagram

Illustrates the wiring configuration for cooling-only installations.

Remote Selector Switch Wiring

Wiring diagram for EWC-ST-2E with MCS-DXB remote selector switch.

Tandem Damper Wiring Diagram

Shows typical wiring for tandem damper installation.

Multi-Damper Control Wiring

Wiring for controlling up to four dampers per zone using an external relay.

Fan Center and Oil Burner Wiring

Diagram for fan center and oil burner with isolation relay.

Gas Furnace Wiring Diagram

Illustrates wiring for a gas furnace setup with the control panel.

Hot Water Coil Fan Control

Wiring for fan control with a hot water coil, including J1 jumper modification.

Heating Only Zoning Diagram

Diagram for zoning in heating-only applications without controlled cooling.

Interconnecting Panels Wiring

Wiring diagram for interconnecting two panels for additional zones.

Thermostat Compatibility

Zone 1 Thermostat Requirements

Details thermostat wiring requirements for Zone 1, specifying 6 wires.

Zones 2 & Higher Thermostat Requirements

Specifies thermostat wiring for Zones 2 and higher, requiring 3 wires.

Thermostat Operation Notes

Important notes on thermostat mode setting and compatibility issues.

Checkout Procedures

Thermostat Circuit Testing

Procedures for checking thermostat circuit voltages in heating, off, and cooling modes.

System Circuit Testing

Guidance on checking continuity in various system circuits.

Damper Circuit Testing

Steps for testing damper motor circuits and voltage readings.

Wiring Diagram for ST-3 E Panel

ST-3 E Damper Motors Wiring

Detailed wiring diagram for ST-3E damper motors.

ST-3 E Transformer and HVAC Connections

Wiring diagram for ST-3E transformer and HVAC equipment connections.

ST-3 E Thermostat Connections

Wiring diagram illustrating connections for ST-3E thermostats.