Replacing Obsolete Damper Motors.
1. Finding or Replacing obsolete Damper Motors,
send us some pictures:
Cant find a replacement motor? Retrozone inc. is the
leader in replacing damper motors, even obsolete motors
that can’ be found. We manufacture a wide range of
adapters and parts to adapt current motors-often far
better than the original motors-to damper applications.
*If its a “Synchron” branded number, all we need is the
5 digit number ending in R or L.
*If we ask for pictures, its best if you can remove the
motor, and take a picture of the bottom of the motor, as
well as where the motor was removed from the device; we
may need to see what motor kit will work. Don’t get too
close, we need a field of view of about a foot where we
can see how much space is available for a possibly
larger motor.
*On obsolete motors, its more important for us to see
the device or damper shaft and surrounding area once
the motor is removed, so we can evaluate what kit to
use, or what special kit to put together. Any
dimensions of the shaft or parts present for us to
attach to may be useful.
*”Motor” on most dampers means the entire motor assembly
(with gears and springs)as it is removed from the damper
drive shaft. Motors part of an motor assembly are
typically not replaceable.
- Dampers used to control
combustion gasses from gas appliances are considered
“life safety” and will usually have extra wires for an
end switch, you may need to replace the entire device
with a UL or other agency certified damper.
- Please
send Photos to support@retrozone.com
2. Replacing the entire damper instead of just the
motor:
- Dampers in rectangular ducts
are typically easy to change by removing a few screws in
the mounting place, and sliding the damper out. This may
be a better option with very old dampers. We can help
you decide what dampers are best suited for replacement
as an option to replacing just the motor.
*Dampers in Round Flexible type “Flexduct” can often be
easily changed as an alternative to replacing just the
motor, if no good motor solution exists. Email us and
we can help you decide which of our dampers is best.
*Dampers in rigid steel pipe can be problamatic, but not
impossible to change. However, a motor kit for these
will often be the best solution.
3. Two wire “spring return” versus 3 wire “power
open, power close” dampers:
- 2 wire “spring return” versus 3
wire “power open, power close” dampers: Chances are you
are replacing a 2 wire spring return damper motor (due
to low cost) which are the most common. However, in
general these spring return motors have a far higher
failure rate, for two reasons:
- A. The motors, when
energized, must pull power all the time to overcome the
spring, and as a result can get very hot.
- B. The Spring tension on
the gears, especially plastic gears, often causes
premature failure. Despite claims, these dampers can
fail in any position.
4. Using a Three wire power open/power close type
damper to replace a two wire “spring return” damper
motor.
You can replace with a Three wire damper in most cases
if you already have, or can get, a third wire from the
damper motor to the zone panel, thermostat, switch, or
other control device. This is true even if your zone
panel has only a 2 wire damper output; we will tell you
how to hook up the third wire.
Our three wire “power open power close” dampers only use
power when moving, never get hot, and have no spring to
wear and tear on gears, so its the way to go in most
applications.
5. Can I use a thermostat on a three wire power
open/power close damper without using a relay? How does
that work?
Yes you can, all of our three wire dampers may be used
with a simple, conventional thermostat with no relay
needed. Power is wired to terminals 1 and 2 on the
motor full time (but its only used when the damper is
moving), and then 3 is wired to the thermostat Y or W or
both. See “slave zone diagram” for more information.