EWC Controls EWT-3900 Technical Bulletin

TECHNICAL BULLETIN

Model EWT-3900

Wireless Programmable Digital Thermostat

Installer : Save these instructions for future use!

FAILURE TO READ AND FOLLOW INSTRUCTIONS CAREFULLY BEFORE INSTALLATION OR

OPERATION COULD DAMAGE THIS CONTROL OR CAUSE PROPERTY DAMAGE.

DESCRIPTION

The EWT-3900 7Day/5-2 Day Wireless Programmable
Digital Solid State Thermostat uses a microcomputer to
provide precise time and temperature control. This wireless
thermostat offers additional flexibility to design heating and
cooling systems where hard wired installations would be
difficult to do.

The Model EWT-3900 Wireless Thermostat is Linked to
the Receiver at the factory. Simply power up the
Receiver, then program and operate the Thermostat.

Features:

l The Thermostat is powered by a rechargeable lithium-ion

battery.

l The receiver module is powered with 24VAC from a

Control Panel or 24VAC Class 2 Transformer.

l The receiver module terminal block has the following

terminals: R, C, W1/E, W2, Y1, Y2, G, O, B and one
NC (no connection) terminal.

l Compatible Equipment: ULTRA-ZONE Control Panels:

NCM-300, BMPlus3000 & UZC-4.
Single or two stage heating and cooling equipment

Gas, Electric, Oil or Hydronic. One or two stage

compressor heat pump with electric backup.

l Simultaneous heat and cool program storage.
l Program storage is retained in case of power loss.
l LCD continuously displays time and room temperature.

Temperature set point is displayed when it is being
changed.

l Temperature display can be configured in °F or °C.
l The Thermostat can be programmed between

45°F and 95°F.

l Backlit display.
l Air Filter Replacement Monitor.

Electrical Ratings

19-30VAC 50/60 Hz

1.0 Amp (Max load per terminal)

MON

1

DAY/
TIME

PROG

Room

PROG

:

DAY

°

PM

FAN

SYSTEM

HEAT

FAN

AUTO

MODE

HOLD

/RUN

LCD Display: Shows
Time, Day, Temperature
and other system data.

Reviews filter usage
in hours and minutes
and also activates
standby mode.

Soft touch Programming
and Function Buttons

Figure 1

Contents:
1 EWT 3900 Thermostat

1 EWT 3900 Receiver
1 USB Adapter Cord
6 Plastic Wall Anchors
6 #8 x 1” Screws
1 TB-236 Technical Bulletin

Accessories: (not included)
EWT-BC Wall Outlet Charger

Replacement Battery
Replacement Charging Cord

Charging Requirements:

EWT-BC Wall Outlet Charger
PC Computer with USB Port

or

Thermal Ratings

Set point Temperature Range 45°F to 95°F
Operating Ambient Temperature Range 30°F to 99°F
Storage Temperature Range 14°F to 140°F
Operating Humidity Range 0-90% R.H. (Non Condensing)

TB-236 090375A0236 Rev. B

EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX [phone] E-Mail- [e-mail]

Copyright © 2009 EWC Controls All Rights Reserved

ATTENTION

!

This product does not contain mercury. However, this
product may replace a unit which contains mercury.
EWC Controls Inc. would like to advise all technicians
and consumers that all mercury thermostats should
be recycled.

1

INSTALLATION

The installer should be an experienced and trained

HVAC contractor. Failure to read and follow

instructions carefully before installation or

operation could damage this control or cause

property damage. Test the finished installation for

proper operation.

To conserve power, the EWT-3900 leaves the
factory in Standby Mode. When removed from
the box, “PE” will be displayed on the LCD to
indicate Standby Mode. When you are ready to
use the thermostat, press and hold the
round center button for five seconds to exit
Standby Mode.

CAUTION

!

To prevent electrical shock and/or equipment damage,
disconnect electric power to HVAC system at main
fuse or circuit breaker box until installation is complete.

Mounting the Receiver

Mount the receiver with the supplied mounting

screws near the zone control panel or HVAC

equipment to be controlled. Do not mount the

receiver inside the equipment cabinet or any

other metal enclosure. Do not Mount the

receiver in any location than is subject to

freezing and/or condensation.

4.55”

W1

2

W2

C

R

E/

NC

B

Y1

Y

O

G

Mount the EWT-3900 Thermostat about 5 feet
above the floor in an area with good air circulation
and average temperature. DO NOT install the
thermostat where it can be affected by:

drafts or dead spots behind doors and in
corners
hot or cold air from ducts
radiant heat from sun or appliances
concealed pipes and chimneys
on surfaces such as an outside wall, that
are a different temperature than the room
air temperature.

Mounting the Thermostat

ATTACH THE MOUNTING BRACKET TO THE WALL

1. Place the bracket on the wall where you would like

the thermostat to be and mark the two holes with a

pencil.

2. Using a 3/16” drill bit, drill out the marks you just

made on the wall.

3. Insert the wall anchors into the holes pressing flush

with the wall.

4. Place the bracket over the holes and fasten with the

supplied #8 screws.

3.85”

1.78”

Technical Data

Power

Working Environment

Range

Shell

Dimension

Connection Interface

Wireless Frequency

Communication baud rate

Wireless Channels

Communication Distance

Do not use circuits exceeding specified voltage. Higher
voltage will damage control and could cause shock or
fire hazard.

Do not short out terminals on gas valve or primary control
to test. Shorted or incorrect wiring will damage thermostat
and could cause personal injury and/or property damage.

Thermostat installation and all components of the system
shall conform to Class 2 circuits per the NEC code.

AC24V, 50/60Hz

30°F~99°F

0~90%RH(non-condensing)

Fire Retardant PC ABS

4.55x3.85x1.78 in (HxWxD)

Each terminal is capable of accepting

2 x 18 AWG solid copper wires.

433MHz

2.4 kbps

1~10 Channels

Beeline distance 200ft in the field. (The

distance will shorten through walls and floors)

WARNING

!

2

EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX [phone] E-Mail- [e-mail]

Copyright © 2009 EWC Controls All Rights Reserved

WIRING THE RECEIVER TO THE EQUIPMENT

THERMOSTAT TERMINALS (HEAT PUMP)

SYSTEM

C
R

E/W1

W2

Y1

Y2

G

O

B

Heat Pump 1
24 Volt (Common)

24 Volt (hot)

Emergency 1st stage

Auxiliary / Emergency 2nd Stage
Heat and Cool mode 1st stage (compressor)

No output

Blower/Fan Energized on call for Heat and Cool

Energized in Cool Mode

Energized in Heat Mode

Heat Pump 2

2nd Stage Compressor

THERMOSTAT TERMINALS (CONVENTIONAL)

SYSTEM

C
R

E/W1

W2

Y1

Y2

G

O

B

Single Stage
24 Volt (Common)

24 Volt (hot)

Heat Mode 1st stage

No Output
Cool mode 1st stage (compressor)

No output

Blower/Fan Energized on call for Cool (and Heat
if HE was selected)

No Output

No Output

Multistage

Heat Mode 2nd stage

2nd Stage Compressor

UZC-4

Heat Pump 3H/2C

O Reversing Valve

Figure 2

BmPlus 3000

Heat Pump 2H/1C

B Reversing Valve

Figure 3

NCM-300

Gas/Elec. 1H/1C

Figure 4

ZONE
T’STAT

C

R

W1/E

W2

Y1

Y2

O/B

G

ZONE
T’STAT

C

R

W/E

Y

G

O/B

ZONE
T’STAT

C

R

W/E

Y

G

O/B

C

R

NC

E/W1

W2

Y1

Y2

G

O

B

C

R

NC

E/W1

W2

Y1

Y2

G

O

B

C

R

NC

E/W1

W2

Y1

Y2

G

O

B

r
ive

e
c

Re

r
ve

i
ce

e
R

r
e
v

i
e
c

Re

R5

R10

R9

R6

R70

R69

R13

R19

R23

R24

R25

R29

R30

R34

R32

R33

R40

R39

R42

R43

R41

R44

R47

R49

R48

R48

R54

R55

R54

R55

R50

R61

R63

R62

R65

SUPPLY

AIR

SENSOR

ZONE 3

T'STAT

W/E

C

W/E

O/B

Y
R
G

ZONE 2

T'STAT

W/E

C

W/E

O/B

Y
R
G

ZONE 1

ZONE 1

T'STAT

T'STAT

W/E

C

W/E

O/B

Y
R
G

ONE
ZONE

Figure 5

FULLY

ZONED

NCM-3000

2

1

C

R

NC

r
e

E/W1

v

i

W2

e

Y1

Y2

Rec

G

O

B

C

R

NC

er

E/W1

v

i

W2

e

Y1

ec

Y2

R

G

O

B

C

R

RC

02

E

1

O/B

Y2

3

L

WT­E

Y

G

AUX

For detailed wiring info

refer to NCM-300 TB-226

Warning: There should be at least 1 hardwired system thermostat in the home or building to ensure the
ability to control the HVAC equipment in the event of a drained battery or loss of communication.

EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX [phone] E-Mail- [e-mail]

Copyright © 2009 EWC Controls All Rights Reserved

3