Zonefirst MDPA2 User manual

Digi-Zone Adder
Model MDPA2 Ver.04
Installation and Operating Instructions
Controlling Your Comfort Room By Room

MDPA2 FCA112515 ©2012-2015 ZONEFIRST ®Page 2
MDPA2 Panel Features
Table of Contents
Installation ……………………………………….2
Operation .……………………………………….3
Wiring ……...………………………………….....3
Checkout ..…………………………………….…3
Troubleshooting ………………………………...4
INSTALLATION
The Digi-Zone Adder (MDPA2) for Plug-In Dampers is a two (2) zone
control panel that is only used to add one or two additional zones to
the MDP3 Zone Panel. A total of fifty (50) MDPA panels may be
added to an MDP3 Zone Panel to get up to one hundred and three
(103) zones.
When installing the MDPA2 panel it is important to pick a central
location (typically in close proximity to the MDP3 control panel) where
it is most convenient to bring all the wires. Most often this is at the
furnace or air handler. It is often closest to power, the HVAC unit
controls and the zone dampers when typically located at or near the
plenum. However this panel can be located remotely from the main
panel and only requires a CAT 5 cable (supplied with MDPA2) in
order to place remotely.
The MDPA2 panel case is made of sturdy ABS plastic and can be
mounted to any flat surface. It is recommended that the panel be
mounted to a wall or return plenum and NOT on the furnace or
plenum where it will be in contact with the hot temperatures.. The
panel can be located in an attic space or in an enclosed cabinet of a
rooftop unit. Insure the panel is not in direct exposure to the
elements.
The cover easily removes from the case by pulling firmly and
separating the cover from the case exposing the circuit board. There
are 4 key-hole mounting points in each corner of the case. The case
has openings in the rear of the case as well as the side for all wiring.
Wiring can come from the back as well as the side in order to make a
neat installation.
System Indicator LEDs
Power Indicator LED
Zone Terminals for
Zone Thermostats
24VAC Transformer
Terminals
Zone Damper RJ11
Plug-In Connections and
LED Indicators
Adder Panel CAT 5
Plug-In (IN)
Connection From
MDP3
Adder Panel CAT 5 Plug-In
Connection (OUT) To Next
MDPA2
Mounting Keyholes

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 DAMPERZONE DAMPER
WIRING DIAGRAM 1 – Conventional Thermostat
Y
G
C
R
W/OB
E
ZONE THERMOSTAT TERMINALS
C W R Y G
ZONE THERMOSTAT
WIRING DIAGRAM 2– Heat Pump Thermostat
Y
G
C
R
W/OB
E
ZONE THERMOSTAT TERMINALS
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
.

MDPA2 FCA112515 ©2012-2015 ZONEFIRST ®Page 4
TROUBLESHOOTING
The MDPA2/MDP3 is a very simple control to troubleshoot, especially
with the LED indicators. The only other device needed is a simple
Volt/Ohm meter. Almost all problems can be traced to an external
component or wiring to/from the MDPA2. The following procedures
can help isolate the problem.
Zone(s) Not Calling
Each zone has a LED next to the zone damper plug-in jack, when a
zone is calling and that call is being recognized by the MDPA2/MDP3
that zone LED will be illuminated GREEN . Provided no other zone is
calling for the opposite mode, check the zone that is supposed to be
calling and the zone’s LED. If it is not on, check for 24VAC across
the thermostat terminal C and the Y, if a Cool call, W if a Heat Call, or
G if a Fan call. If there is no voltage here at the panel, the panel is
not getting the signal from the thermostat. The problem is mis-wiring,
a broken wire or a problem in the thermostat. To check the zone on
the panel, place jumper from R to Y, R to W or R to G to see that the
panel is operating properly.
Zone(s) Will Not Shut Off
If a zone will not stop calling, the Zone LED should still be illuminated
GREEN. Depending on the call disconnect the Y, W or G wire from
the terminal strip. The zone will drop out. Check the thermostat
wiring for a mis-wiring or short that keeps the zone calling. If the call
remains and the thermostat is disconnected, replace the panel.
Damper Motor Checkout
To checkout the dampers, the panel has a LED for each zone. This
illuminates GREEN when the dampers are to be OPEN, either on a
call or when all zones are satisfied. The damper position is confirmed
by the bi-color LED on the motor. When the panel zone LED is
Green, the motor LED must be Green also indicating the damper
being open. When the panel LED is not lit the damper should be
closed and this is confirmed by the damper LED being Red.
Power LED Not On
If the Power LED is not Illuminated GREEN and there is 24VAC at the
transformer terminals, the MDPA has a built-in thermal fuse, (light
brown rectangle component below transformer terminals) that may be
open. To check, touch to see if component is hot. If it is hot, fuse is
open and must be reset. This is also indicative of a potential wiring
short.
Remove all wires (start with transformer wires) from the MDPA2
panel and check fuse (must be cool to the touch) to make sure it is
not hot. Place 24VAC wires back to transformer terminals on panel
and power LED should come back on. If it does not, replace board.
If it does light, begin adding the wires from each zone to the panel
one by one checking the power LED at each point. If the power LED
drops again check these wires for a potential short.
TRANSFORMER PHASING
When using separate transformers to power the MDP3 and MDPA2
panels it is required that all transformers be in phase with one
another. To check the transformer phasing use a voltmeter and
check for voltage on one leg of the 24V transformer connection on the
MDP3 panel to the opposite leg of the 24V transformer connection on
the MDPA2 panel. See the diagram below. The voltmeter should
read zero (0) Volts. If the voltmeter reads 24V or 48V, reverse the
leads of one of the transformer until the voltmeter reads zero (0) volts.
Reading zero volts proves the transformers are in phase with one
another.
MDPA2 Panel Wiring Diagram
20 Bushes Lane •Elmwood Park, New Jersey 07407-3204
USA
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www.zonefirst.com [e-mail]
R
C
24VAC 2
24VAC 1
R
C
24VAC
24VAC
0V
AC
MDP3
MDPA2
24V 40VA
Transformer
Voltmeter
24VAC 2
24VAC 1
24VAC 2
24VAC 1
0V
AC
24V 40VA
Voltmeter