Please note: We offer two Belimo kits designed to replace the SUB motor at about the same cost, which mount a far more robust Belimo commercial motors in the place of the old Synchron motor. Both Belimo kits carry a 5 year warranty and will far outperform the original motor.
for the obsolete or difficult to find 39154R motor.
This is another quality substitution motor that we have developed to keep you damper going and not require full damper replacement. Quality Synchron motor has very similar specification to the 39154R motor you are replacing.
Installer will need to drill out end of hollow aluminum damper shaft about 1/4 inch with a 21/64, 11/32 or similar size bit, to allow brass nose on shaft to enter shaft so motor will fully seat on damper. A 21/64 drill bit will be supplied with this motor.
Since the shaft material is both aluminum and already hollow, this is typically not difficult if carefully done.
Another method to mount the motor is to install washers under the mounting screws of motor, to elevate the motor so the brass nose piece does not interfere with the damper shaft. While his eliminates the need to drill the end of the shaft, it may cause a shorter life span of the motor, especially on larger (12 inch and above) dampers. The washers are NOT needed if the drilling method described above is used. Use the drilling method if practical.Also look at ourKit 4 Belimo replacement Motor for this application.