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Table Of Contents

DIP switches select

options and type

of HVAC system.

LED indicators show

the system status.

Circuit breaker

type fuse.

Intelligent microprocessor

control

Expands up

to 29 zones

The UZC3C is a universal HVAC control panel that provides

intelligent control of forced air zoning systems up to 29

zones using motorized dampers. Controls 3-stage heat

and 2-stage cool, gas,oil / HVAC or heat pump systems.

Compatible with virtually any off the shelf thermostats. With

such features as supply air limit control, auto- changeover,

watch dog system monitor, and remote zone override.

Other features include mild weather inhibit feature,

humidifier, combustion damper or fresh air control. The

UZC3C provides the highest level of zone control

performance yet released by EWC Controls.

Main panel controls 3 zones and may

be expanded to 29 zones, using the

UEX-22, 2 zone expansion panels.

Controls up to three stages of heating

and two stages of cooling using

gas/oil fired furnaces with electric air

conditioning or heat pumps.

Compatible with any mechanical or

electronic thermostat that operates

on 24VAC, battery powered, or power

robbing type that draw less than 25

ma of current. Single or two-stage

heat/cool, or heat pump type

thermostats can be used. All

thermostats must have a switching

subbase.

The UZC panel features automatic

changeover from any thermostat

allowing for individual zone comfort of

the HVAC system.

The UZC3 has a number of LEDs that

indicate the status of the HVAC system

and the UZC3 panel. The function of

each system LED is described in the

Service Guide.

LEDs indicate which zone dampers

should be open.

Operates on 24VAC power supplied

from a separate transformer. A single

40VA class 2 transformer can power

five zones, or a total of 5 dampers.

8VA draw per damper.

The UZC3 has a thermal circuit

breaker in place of a fuse which

protects the panel from shorts in the

thermostat and damper field wiring. It

does not protect against shorts in the

system field wiring.

When the circuit breaker is tripped it

will get quite hot. To reset the breaker,

remove the 24VAC power for

approximately 30 seconds.

Zone Capacity

Compatible

HVAC Systems

Compatible

Thermostats

Automatic

Heat/Cool

Changeover

Figure 1. UZC3 panel features.

LED Indicators

Damper LEDs

Operating

Power

Thermal

Breaker

Caution:

EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-635-8646 E-Mail-info@ewccontrols.com

TB-205 Model UZC3C

LEAVE THIS BULLETIN ON THE JOB SITE FOR FUTURE REFERENCE

MOV2 MOV3 MOV4 MOV5

DMPR1 DMPR2 DMPR3 AUX RELAY

K11

MODEL UZC3C

3-ZONE CONTROL PANEL

C18

C15

C10

U20

C11

C14

D28

D22

D16

D35

D29

D23

D17

D10

D36

D30

D11

D37

D31

D25

D19

D12

D38

D26

D20

D13

D33

D27

D21

RN9

RN12

RN13

RN14

RN10

RN11

D14

D15

ZR1

D40

D34

D41

R33

C16

C17

C13

R31R29

R27

R30R28

R26

R36

R38

R37

R39

RN4

RN8

RN5

RN3

RN2

RN1

RN7

EXPANSION

C12

FCONT ALLZC

SYS PNL

OFFON

FA MIN/HR

0 32

OSC1

RN6

C19 C20 C21 C22

D32

D24

D18

D39

EM SWYES NO

NOT USED

SYSTEM

RESET

OP SYS

TIMER

1 2 3 4

One zone control override

Multi function

auxillary relay

feature

Watch Dog protection

The panel has a built-in circuit that

monitors the computers performance

and resets the panel if an error occurs

in operation or due to power failures.

Watch Dog

Circuit

Indoor Fan

Control

The fan can be activated from any

zone or from zone 1 only. (Optional)

P/N 090375A0205 REV. H

Summary of content (16 pages)

PAGE 1
TB-205 Model UZC3C LEAVE THIS BULLETIN ON THE JOB SITE FOR FUTURE REFERENCE Automatic Heat/Cool Changeover The UZC3 has a number of LEDs that indicate the status of the HVAC system and the UZC3 panel. The function of each system LED is described in the Service Guide. Damper LEDs LEDs indicate which zone dampers should be open. Operating Power Indoor Fan Control Operates on 24VAC power supplied from a separate transformer.
PAGE 2
EL Set the switch to the GAS position to activate the fan during a cooling call only. (Gas/Electric, Heat Pumps) 3 3 ON ON ZC ALL ALL 2 4 ON O B 4 O ON Heat Pump Reversing Valve B DIP switch 3 selects whether all zone dampers open during a continuous fan call or, only the zones calling for continuous fan will open. Set the switch to the ZC position to open only the zones calling for continuous fan operation.
PAGE 3
Selecting the Auxillary Relay Function PNL 2 ON 2.0 3.5 2 2.0 ON 2 or 3.5 Minute Panel Purge Time 3.5 6 ON ON DIP switch 1 selects either system controlled or panel controlled purge, at the end of a heating or cooling cycle. Set the switch to the SYS position allows system controlled purge cycle. OFF AUXRLYA ON 7 1 ON SYS PNL 1 SYS ON System or Panel Purge Control ON DIP SWITCH BANK “B” DIP switch 6 and 7 selects one of the following functions of the Auxillary Relay.
PAGE 4
Auxillary Relay Not Used 6 ON AUXRLYB ON When both DIP switches are set to ON, the Auxillary Relay is not being used. OFF EM HEAT OFF ON 7 ON AUXRLYA ON OFF DIP switch 8 selects either a 5 or 10minute delay before the opposite system can be activated to prevent rapid cycling between heating and cooling. 8 8 ON 5 ON Selecting the Changeover Time Delay 5 Emergency Heat Switch 10 Set the switch to the ON position for a 5-minute changeover delay.
PAGE 5
Built-In Timer Settings The panel has built-in timers that insure reliable operation. ZONE THERMOSTAT Mo 10:30 AM 68 Cool Short Cycle Timer 2 minutes, fixed FAN Minimum Call Timer 2 minutes, fixed ON W2 Short Cycle Timer Changeover Timer Be sure to set the O/B DIP switch to correspond with the O/B output of the thermostat. Mo W1 W2 50 TSTAT 1 80 80 W2 Y2 EM G W1 O/B 70 60 50 G W Y AM 68 Y2 EM ON AUTO G B COOL OFF HEAT O Y1 EM. HEAT C R W2 Y2 EM G W1 O/B Figure 5.
PAGE 6
ZONE THERMOSTAT Mo 10:30 AM DUAL FUEL SET-UP w/OAT 68 Cool FAN ON W2 Y2 G W1 COOL OFF HEAT Y1 C EM. HEAT HEAT PUMP 1 STAGE R X O Y C R TSTAT 2 W2 Y2 G W1 Y1 AUTO 30 DEG. F. SPDT OUTSIDE AIR T’STAT B R W GAS FAU 2 STAGE W2 C R W1 Y G Figure 7. Typical two-stage heat-cool thermostat wiring. HVAC System Wiring C R On the UZC3 panel, the fan (G), the compressor (Y1) and the reversing valve (O/B) are powered by the RC terminal. The heating (W1) is powered by the RH terminal.
PAGE 7
+ 8 F1 E D C B A + 6 TRANSFORMER 24V, 40VA ZONEA 5 + E D C B A 4 F1 ON Y2 T W2 S G T Y1 A T W1 4 C R C9 D M P R 1 2 3 4 5 E D C B A 1 2 3 4 5 E D C B A D M P R ON ZONEB 3 5 E D C B A ON E D C B A Y2 T W2 S G T Y1 A T W1 5 C R 1 2 3 4 5 OUTPUT ON 4 1 2 3 4 5 Jumper cable. MODEL EWC UEX22 ON DIP switch settings for second expansion panel.
PAGE 8
Damper Wiring Spring Return Figure 15 shows how to wire a spring Motor Wiring return damper. A normally open style The damper motor terminals (M1, M2, M4 and M6) will accommodate practically any 24VAC motorized damper. Damper motor selection should be limited to motors with less than .5 amp current draw. damper is wired to M1 & M6. Normally closed style damper is wired to M1 & M4.
PAGE 9
HUMIDIFIER M2 COM A U COM X NC I L NO L M2 A R M1 Y Selecting Combustion Damper Control AUXRLYB ON OFF AUXRLYA ON The auxiliary relay contacts can be used to activate a combustion damper that opens whenever there is a call for heating. Figure 20 illustrates an ND damper used as a combustion air damper. OFF DO NOT CUT JUMPER Figure 17. Humidifier wiring diagram. If a humidistat is used for monitoring relative humidity, it should be wired as shown in figure 18.
PAGE 10
One Zone Control The One Zone feature allows the occupant to control all the zones from a single thermostat by setting the switch on the panel to ONE or using an external switch connected to the One Zone terminals shown in figure 22. A homeowner can switch to One Zone control when they leave for vacation, and the Zone 1 thermostat will control all zones. All zone dampers will respond to the Zone 1 thermostat.
PAGE 11
The SUPPLY LIMIT LED is on continuously when the supply air temperature has exceeded the high or low temperature limits. The LED will blink if the panels detects an open or missing sensor or a shorted sensor. ONE ZONE The ONE ZONE LED indicates when the panel is in "One Zone Control" mode. DMPR1 DMPR2 DMPR3 The DMPR LEDs indicate when the panel has activated the relays controlling the damper motors.
PAGE 12
SERVICE GUIDE Some Helpful Guidelines Voltage measurements on the panel at the damper terminals and thermostat terminals, should be made with the ground lead of your meter on terminal 1 of the 24VAC input terminals. All VAC measurements at the HVAC system terminals should be made with the meter ground lead on the HVAC system's C or common terminal at the HVAC system. Damper LED The DMPR1, 2 and 3 LEDs indicate that the relay controlling the damper motor is activated.
PAGE 13
Table 1. Detecting 24VAC Shorts and Loss of +5VDC or +24VDC Detecting 24VAC Short The STATUS LED will be off, you will measure 24VAC at the transformer terminal 1& 2, but not at any damper M1& M2 terminals or any zone thermostat R & C terminals. The thermal fuse will be very hot. Isolating 24VAC Shorts Panel or Wiring Remove the wire at each zone thermostat R terminal on the panel and test, if the short still persists. If the short disappears, check the zone thermostat field wiring for shorts.
PAGE 14
Table 3. Trouble Shooting Heating, Cooling and Fan Problems LEDs On But System Not Responding Check the HVAC field wiring to insure it is correct. Be sure all wires are secured in the terminals. Check that there is 24VAC at the RC and RH terminals. Use the HVAC system common (C) as the ground lead of your meter. A jumper is provided near the system terminal block, to isolate for dual transformer systems.
PAGE 15
WIRING DIAGRAM FAN AUTO Control Panel SYSTEM ON COOL OFF HEAT 70 60 80 80 Model UZC3C ND/URD ZONE 5 THERMOSTAT 50 1 4 6 70 60 MODEL EWC UEX22 1 2 3 4 5 5 D M P R ZONE 4 THERMOSTAT FAN AUTO SYSTEM ON COOL OFF HEAT 70 60 80 80 F1 + C9 4 Y2 T W2 S G T A Y1 T W1 4 C R Y W R 50 ZONEB ND/URD E D C B A 50 G Y2 T W2 S G T A Y1 T W1 5 C R ZONEA D M P R ON 1 4 6 OUTPUT 70 60 50 Jumper cable R4 MODEL UZC3C 3-ZONE CONTROL PANEL Y W R 16 R38 R39 AUX RELAY 0 1 4 6
PAGE 16
ND 2 3 URD 1 6 EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-635-8646 W2 W1 Y2 Y1 O G C R AIR HANDLER Y2 Y1 O R C X/W Z 1 4 6 1 4 6 X HEAT PUMP 2 STAGE Jumper Wire 5 JUMPER Figure 27 UZC3C wiring diagram E-Mail- info@ewccontrols.com 1 - Common 2 - Hot TRANSFORMER 24V, 40VA 0 32 NO YES EM SW ZC FCONT ALL PNL OFF OFF SYS ON ON Control Panel EXPANSION All wiring should be done to local and national codes and ordinances.