DAMPER WIRING CONTINUED
If you need to connect numerous dampers to a single zone, or you are using dampers of unknown current draw
such as Spring Types, Isolation relays and separate power supplies may be required. Parallel as many dampers
as you want as long the total current load of the motor actuators does not exceed the VA rating of the
transformer. Other factors should also be considered, such as the full load amp rating of the isolating relay
contacts, voltage drops from long wire runs and feeder conductor sizing to junction points.
NOTE: Some older style dampers and competitor’s dampers cannot be paralleled and must be isolated or wired
in tandem. Contact EWC Controls Technical Support for assistance.
EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-446-5362 E-Mail- [email protected]
Non-inherently current limiting transformers must have field provided over-current protection on the secondary 24 vac output. The table values
provided pertain to genuine ULTRAZONE Dampers and Competitors typical 24vac Spring loaded dampers. Included in these VA load ratings are the
correct number of thermostats, the BMPlus Zone System, and a 5% field factor. Spring loaded dampers draw higher currents & require more power.
BMPlus 3000, 5000, 7000, Revision “B” Recommended Power Solutions
T E S T I N G D A M P E R MOTORS
SR / ESR / RSD Power Open / Spring Close Dampers
- Connect 24vac common & hot to the two motor (M) terminals.
Damper should Open. Remove 24vac hot. Damper should Close.
ND / URD / SMD / BMD Dampers
- Connect 24vac common to terminal 1 and 24vac hot to terminal 4. Damper should
Open. Remove 24vac hot from terminal 4 and apply to terminal 6. Damper should Close.
RDN / SMDL / BMDL Dampers
- Connect 24vac common to terminal 1 and 24vac hot to terminals 2 and 4. Damper
should Open. Remove 24vac hot from terminal 4. Damper should Close.
SR / ESR / RSD Power Close / Spring Open Dampers
- Connect 24vac common & hot to the two motor (M) terminals.
Damper should Close. Remove 24 vac hot. Damper should Open.
9
Spring Types
@ 8 VA
per damper
ND / URD’s
@ 2 VA
per damper
Transformer Size
60
VA
75VA
30
22
19
26
15
23
40VA
12
9
5
These charts show the maximum
number of dampers that can be
connected to the entire
BMPlus3000/5000/7000 based on the
transformer being used.
Maximum number of dampers
per ZONE is 12.
Use Class 2 UL Listed 1585 Inherently
current limiting transformers only!
Figure 18
Variations on this diagram and other damper solutions are available.
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
ZONE
MOTOR
M1
M6
M4
M2
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
6
4
1
PC
PO
COM
12 Dampers wired to a single zone.
BMPlus
3000
Z
o
n
e
P
a
n
e
l
BMPlus
5000
BMPlus
7000
Transformer Size
60
VA
75VA
7
5
4
6
3
5
40VA
3
2
1
BMPlus
3000
Z
o
n
e
P
a
n
e
l
BMPlus
5000
BMPlus
7000
