FORM 2045-2 1306 ©2013 White-Rodgers by Permission
37-6864B
3
Stage Timer
The CZ-4 has a built-in stage timer that eliminates the need and
added cost of using two stage thermostats. On a call for either
heating or cooling the timer begins. A minimum of 5 minutes,
adjustable to a maximum of 23 minutes, can be set in order to
activate the W2, W3 and Y2 outputs after the first stage call.
The Stage Timer is marked 0 through 9 and each increment is
indented as the dial is rotated. A minimum 5 minutes is set when the
dial is set to 0. To calculate the stage timing the dial setting is
multiplied by 2 and added to the base of 5 minutes. Example: Dial
setting is 3 x 2 = 6 + 5 = 11 Minutes for the Stage Timer.
When any zone calls the timer starts and activates the second stage
W2 or Y2 after the set time elapses. The timer also controls W3 after
the same time elapses after the W2 call.
PURGE TIME
The CZ-4 has a built-in Purge Time after each call is satisfied and
provides a minimum off time before another call is initiated. The
Purge Time is set at 2.5 minutes after all calls for a particular mode
are satisfied or when the Changeover Timer requires a changeover
due to opposing calls.
After all calls are satisfied or the changeover timer activates, the
Purge Timer begins and the heating or cooling, whichever was on, is
deactivated. Typically the fan may be running during this time and
the damper(s) to the last zone(s) calling will remain open to purge the
conditioned air only into those zones that were calling for the
conditioning. DIP Switch 5 can be set ON to keep the Fan running
during the Purge mode in order to prevent the fan cycling off and
back on between modes. In the instance where the Fan staying may
create a draft, and the frequency of opposite calls is minimal this
switch can be kept to OFF.
The CLR PRGE button on the top left of the panel can be pushed to
override the Purge mode and speed installation and checkout. This
button is only active when the System LED is AMBER.
Minimum On Timer
The CZ-4 also has a minimum on time whenever the compressor
operates in order to prevent frequent short cycling. Once there is a
call for cooling or the compressor on a heat pump, the CZ-4 will hold
that call for a period of 2 minutes.
CHANGEOVER TIMER
Whenever a call is made for either heating or cooling, the changeover
timer is activated in order to track the amount of time heating or
cooling is on. When an opposite call is made, after an opposite call
exists, the changeover timer calculates the amount of time the unit
has already been supplying the first mode in order to determine how
long it will hold off the opposite call. If an opposite call is made
shortly after the first call, the opposite call may be held off for as
much as 20 minutes. If the first call or subsequent calls for the first
call mode has had that mode operating for up to 20 minutes already
and an opposite call comes in after 20 minutes, the changeover timer
will immediately recognize the opposite call, shutting off the current
mode, enter the purge mode and automatically switch to the opposite
mode.
The longer a call has been running up to 20 minutes, the shorter the
wait time will be for an opposite call. If a call is over 20 minutes and
an opposite call is made the changeover will be immediate following
the purge time. This intelligent changeover timing makes the CZ-4
unique to any other zoning system.
Zone Adder Control (CAZ-2)
The CZ-4 Zone Panel can be added onto with the Model CZA. The
CZA is available as a 2 zone adder panel and expands any CZ-4
panel to a maximum of ten (10) zones. The CZA panel is connected
by a 6 conductor RJ11 telephone cable. This makes wiring between
the CZ-4 and CZA literally a snap.
CHECKOUT
The CZ-4 has unique features that simplify the checkout of the
system and has LED readouts that constantly indicate the system
operation. Once 24 Volt Power is applied to the panel the Green
Power LED will illuminate. This will stay illuminated constantly when
power is applied.
The System LED will provide several different indications based upon
color and if it is flashing.
Heat ON – RED
Heat Limit – RED Flashing
EMG Heat (HP Mode Only) – RED Flashing
Cool ON - GREEN
Cool Limit - GREEN Flashing
Fan ON - AMBER
Purge/Time Delay – AMBER Flashing
Each zone has its own small Green indicator LED next to each zone
relay. This light is lit when the specific zoning is calling for the mode
shown on the System LED.
WIRING
The CZ-4 is very simple to wire and requires only a minimum number
of connections. The CZ-4 terminal blocks are screw-less and all
wires can easily be pushed into their respective terminal by de-
pressing the button for each point and releasing once the wire is
seated. To remove the wire, just press its button again and remove
the wire.
WIRING DIAGRAM 1 –
Single Stage Thermostat
C W R Y G
E
G
Y
R
W/O/B
C
CLOSE
OPEN
COM
ZONE
CONNECTIONS
T
HE
RM
O
S
T
A
T
DA
M
P
E
R
Single Stage Thermostat
WIRING DIAGRAM 2 –
Single Stage, Two Stage and
Three Stage Heating Equipment and up to Two Stage Cooling
W2
W1
Y1
Y2
O
G
E
B
R
First Stage Cooling Relay
24V. Transformer
Second Stage Cooling Relay
First Stage Heat Relay
Fan Relay
EQ
U
IP
M
EN
T
HEATING COOLING EQUIPMENT
Second Stage Heat Relay
W3
Third Stage Heat Relay
STG Time
5 MIN + 2X
CLR
