![motor winding heater motor winding heater](https://images.slideplayer.com/26/8829835/slides/slide_9.jpg)
#Motor winding heater series
The MWH Series then goes back on-line after the overload relay is reset.
![motor winding heater motor winding heater](https://www.flexheaters.com/images/applications/motor-heaters.jpg)
This will disable the motor winding heater control, preventing any additional heating in the motor and allowing for a faster motor cool down period. auxiliary contact on the motor starter’s thermal overload relay. The MWH Series had an optional shutdown input that can be connected to the N.O. When the motor is restarted, the MWH Series instantly turns off. A built-in one minute timer ensures that the motor magnetic field has collapsed before it injects DC power into the windings. Fully Automatic Operationĭesigned for fully automatic operation, the MWH Series turns on when the motor starter has turned off. A metal oxide varistor (MOV) protects the unit against voltage spikes for reliable, maintenance-free operation. In addition to built-in fuse protection, the MWH Series features an RC snubber circuit across the SCR which protects it from any rapid rate of change in the system voltage. This adjustment can be used to trim the control as required for each application. Output voltage is factory set to maintain a +5° to 10☌ differential above ambient temperature. Just wire it in parallel to the magnetic starter’s line and load connection, connect the necessary auxiliary contacts and installation is complete. If that is the case, you won't know if you have the correct connection until you put a load on the motor.Whether retrofitting an existing starter or installing a new one, the MWH Series is easy to apply. Either connection may be viable with no-load operation. It is possible the either connection may appear to work. Disconnect if it seems to be heating up to much or too quickly. If you determine which connection seems to be better, check the temperature of the motor carefully during initial operation. That also indicates the relative current in each winding. If some windings use larger windings, you can be sure those are part of the main winding. If you can, look at the size of the wire used for the motor windings. Switch off immediately if either the ammeter or the sound of the motor is not what you expect. Connect the motor through a switch that is easy to operate and close to the ammeter. However you do need to be aware that for the first fraction of a second, the current will normally be quite high. It will be easier to instantly see a problem with an analog meter.
![motor winding heater motor winding heater](https://img.yumpu.com/18799962/1/500x640/dahlander-motor.jpg)
Clamp-on ammeters are available at a reasonable price and very good to have for anyone who does electrical DIY projects etc. If you want to proceed on the basis of someone's best guess, have an ammeter in place during the test. On the other hand, if the 4 ohm winding is assumed to be the main winding and the self inductance is not as high as it would be for a main winding, the current could be too high. If the motor takes 5 amps and most of it goes through the 16 ohm winding, that would mean 400 watts dissipated in the winding. That seems like a lot for a motor that might require only 400 watts in normal operation, but motors of that size and type may have only 50% or 60% efficiency. If it is as little as 2 amps, the lost heat in the 16 ohm winding would be 48 watts. Another reasonable alternative would be to examine or find documentation for a similar appliance.īecause of the water heater in most dishwashers, it is difficult to determine from sales literature how much current the pump motor draws. The best way to determine the connection remains identification by examination of the original wiring. That is obviously not the case here, but that illustrates the extent of variability PSC motor designs. I know that there are PSC motors that are designed with two identical windings to make it simple to reverse the direction of rotation. All dishwasher motors are likely to be similar, but not necessarily the same as furnace blower motors. Appliance and equipment motors have undergone many years of optimization to produce motors that are exactly suited to the load with minimum cost.
![motor winding heater motor winding heater](https://patentimages.storage.googleapis.com/fe/b9/98/350f204be56c96/US20130271060A1-20131017-D00000.png)
However the guides I saw seemed to refer to specific purpose motors, heating and A/C fan motors, I think. I have seen a couple of trouble-shooting guides that say the opposite. I have started to doubt my thought that the lower resistance winding would be the one with the additional capacitive impedance in series.