MDPA2 FCA112515
©2012-2015 ZONEFIRST
®
Page 3
OPERATION
The MDPA2 is an extension of the MDP3 zone functions. The
MDPA2 must use the same thermostat wiring configuration as the
zones on the MDP3. The MDPA2 is not used as a stand alone
panel.
On a call for heating or cooling, the panel will accept the first call from
any zone, providing no other calls for heating or cooling exist in the
system Upon accepting this call the MDPA2 will open its zone
damper(s), if not open already, close the damper(s) to those zones
not calling, activate the needed HVAC controls for heating or cooling,
whichever is being called and not accept any calls for the opposite
mode.
Any calls for the opposite mode will be locked out until the initial
mode is either satisfied or a period of time has elapsed that is
sufficient for the first mode to satisfy, a maximum of 20 minutes. A
Patent Pending sequence determines the time the unit has been
running or needs to continue to run in order to adequately provide
conditioning for each mode. If a particular mode has already been
calling for 20 minutes or longer and an opposite call comes in the
MDPA2 will immediately drop the mode, enter the purge mode in
order to dissipate the conditioned air into the zones calling before
switching over to provide the new conditioning call to its zones.
All other functions are identical to the MDP3 zone operation, see the
MDP3 installation and operating instructions for further details.
.
WIRING
The MDPA2 is very simple to wire and requires only a minimum
number of connections. The MDPA2 color coded 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 it's button again
and remove the wire.
Zone Dampers
–
The MDP3 provides DC power to ZONEFIRSTs'
exclusive Plug-In Zone Dampers. These dampers use and are
supplied with a modular cord that is complete with RJ11 jacks on
each end of a 25’ cable for each zone damper. Up to 10 dampers
can be wired to each zone.
The panel has a GREEN LED to indicate when the damper should be
open. Each damper motor has a two color LED that a positive
indication of the damper being open or closed. When the LED is
GREEN the damper is Open. When the LED is RED the damper is
closed.
ZONE DAMPER
ZONE DAMPER
WIRING DIAGRAM 1
–
Conventional Thermostat
Y
G
C
R
W/OB
E
ZO
NE
T
HE
RM
O
ST
AT
T
ERM
IN
A
LS
C W R Y G
ZONE THERMOSTAT
WIRING DIAGRAM 2
– Heat Pump Thermostat
Y
G
C
R
W/OB
E
ZO
NE
T
HE
RM
O
ST
AT
T
ERM
IN
A
LS
C O/B R Y G E
ZONE THERMOSTAT
Zone Adder Connection
– The MDPA2 panel communicates with
the MDP3 using a CAT 5 cable. A four (4’) foot CAT 5 cable is
supplied with each MDPA2 panel. This cable is connected to the
modular plug on the left side of the MDPA2 panel and the other end
connected to the connector on the right side of the MDP3 panel. Up
to 50 additional MDPA2 panels are connected in the same way in a
daisy chain from one MDPA2 panel to the next.
Transformer
– A 24VAC, 40VA transformer is required to power
the panel. This transformer is wiring to the 24VAC: C and 24VAC: R
terminals on the lower left corner of the panel. Before wiring to the
MDPA2 panel, check the phasing of this transformer with the
transformer that powers the MDP3 panel. Ensure that both
transformers are in phase with one another. See directions on page
4.
CHECKOUT
The MDPA2 has unique features that simplify the checkout of the
system and has LED readouts that constantly indicate the system
operation.
POWER LED
is constantly illuminated
GREEN
when 24VAC is
applied to the MDPA2. The power LED will flash green when the
MDP3/MDPA2 is in the test mode.
HEAT LED
is constantly illuminated
RED
when MDP3/MDPA2 is
calling for the first stage of heating, will flash two times (2X) when
second stage heat energizes and will flash three times (3X) when the
third stage of heat or emergency heat is energized.
COOL LED
is constantly illuminated
GREEN
when the
MDP3/MDPA2 is calling for the first stage of cooling and will flash two
times (2X) when the second stage of cooling is energized.
FAN LED
is constantly illuminated
YELLOW
when calling for the fan
or when the compressor is running.
ZONE DAMPER LEDs
will constantly be illuminated
GREEN
when no zone is calling and indicating the zone dampers are in the
open position.
.
When a zone calls for heating, cooling or fan that zone
LED will remain illuminated and those zones not calling the LED will
go out, indicating that the zone dampers are in the closed position
.
