EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-446-5362 E-Mail- [email protected]
14
SYSTEM WIRING CONTINUED - Specialty Applications
Variable Speed
AIR HANDLER
with 1 or 2 stage Heat
AND
DEHUMIDIFICATION
CAPABILITY
1 or
2 STAGE
HEAT PUMP
UZC4
W2
W1
RH
RC
Y2
O
Y1
G
RC/RH
LINK
RC/RH
LINK
B
E
H
V
A
C
-
S
Y
S
T
E
M
W
O
Y1
C
R
Y2
NC
NO
C
A
U
X
R
L
Y
W1
Y1
C
R
O
W2
Y2
G
DH
HUM
Wiring for typical 3 stage Heat,2stage cool Heat Pump. Diagram reflects De-humidification
terminal wired to the Auxiliary input. Auxiliary Relay Dip Switch #5, Bank #2, should be set
to (RA) Reverse Acting. Contact EWC Controls Technical support or visit our web site for
additional diagrams and alternate control methods to achieve De-humidification.
Using the UZC4’s Auxiliary Feature to control Dehumidify Operations
The Auxiliary Feature
can be used to
activate DeHumidify
Operations on
Variable or Constant
Speed HVAC Systems.
The UZC4 can be set up
to control DeHumidify
operations on most any
H e a t P u m p o r
Conventional HVAC
system. The UZC4 will
also activate a unique
D e h u m i d i f y C o n t r o l
Algorithm when the De-
humidify demand is
d e t e c t e d . W h e n a
separate control calls for
Dehumidification, the
UZC4 will activate “Y1”,
“G” and the Auxiliary
Relay, to signal the Air
Handler to slow the fan
down.
The UZC4 WILL ALSO
e n e r g i z e t h e ( E )
E m e r g e n c y o u t p u t
terminal to REHEAT the
cold discharge air and
Rapidly Dehumidify the
home. Energizing the
“E” during this cycle
prevents over-cooling
the home. A common
Customer complaint with
the DeHumidify cycle in
these HVAC systems.
NOTE1
:
The UZC4 will not
a c t i v a t e d e h u m i d i f y
operations unless the “Y1”
(cool) signal is also detected
at Zone 1.
NOTE2
:
A cooling or heating
demand detected at any other
zone can cause a delay to
activate or will terminate the
De-Humidify operations.
NOTE3
:
Dehumidify can only
be achieved In (RA) Reverse
acting mode.
NOTE4
: Do not use this
f e a t u r e f o r c o m m e r c i a l
applications per ASHRAE
90.1-2013.
DHUM
G
R
O/W2
C
THERMIDISTAT
3 Heat 2 Cool HEAT PUMP
CONFIGURATION
C
W2
Y1
R
G
O/B
ONE
ZONE
ZONE 1
T'STAT
W1/E
Y2
AUX R
CO
2
CO
2
Carrier
Bryant
R
W / W1
Y / Y2
Y / Y2
Y1 / W2
Y1 / W2
R
Wiring for typical 4 stage Heat,2 stage cool Heat Pump. Diagram reflects De-humidification
terminal wired to the Auxiliary output (NC) Normally Closed terminal. Auxiliary Relay Dip
Switch #5, Bank #2, should be set to (RA) Reverse Acting when using the type of control
shown below.
This type of control uses (RA) reverse acting
logic to signal De-humidify demands.
Figure 21.
Figure 22.
