Electrical Wiring in the Home/Connecting a switch to a reversable motor
I have a reversible motor from an old set of drapes.
I would like to mount that motor on some thing else.
The motor has two terminals. Red and black. When the power is applied with no switch. This is with black to black motor turns to the right. When wires is reversed motor turns to the left. I bought a reversible switch with four terminals. How do I connect the switch so as to have the motor turning to the left or right?
The only way two motor leads can be reversible is if it is DC AC won't reverse by swapping hot and neutral, it has to be cone internally in an AC motor,
Now was there a switch on the original drapes?
I am wondering what type of power you are applying to the motor [less switch] ? Is it rectified like from a power cord for a computer, where depending on brand, the power is rectified on the cord, that has the large box in the middle of the cord?
This supplies DC to the computer, other brands put the rectifier inside the computer and also a transformer to lower the voltage to typically 5 volts DC.
I am trying to figure out if the rectifier is in the motor, or somehow you are supplying DC to the motor [less switch]
I understand it reverses, but how is it doing it? Somewhere there is a rectifier, either you are supplying AC and the AC is immediately rectified then swapped positive to negative, like automotive applications
Is the new device you are going to use this motor on, going to use the same current or less than the drapes?
What I dont want is a mismatch of currents especially with the inrush currents it don't matter if it is a .0001 HP or a 1000 HP motor, the rules apply.
Unless this was a HUGE set of drapes, it is a relatively low current event.
I don't know your background, so I am not trying to be insulting, maybe you know all this already, switching AC CAN BE DIFFERENT THAN SWITCHING DC
IS THE SWITCH CAPABLE OF HANDLING THE INRUSH CURRENT!?!!!!!!!!!
EXAMPLE A POLE [reversing but not necessarily] SWITCH MIGHT BE FOR SOME KIND OF RESISTIVE LOAD, you have an inductive load, way different.
THIS MOTOR REVERSES, SO WHEN IT DOES, EACH TIME IT STARTS IT DRAWS 4 TO 8 TIMES THE NORMAL FULL LOAD CURRENT. So it gets the inrush every time it reverses, which should limit the amount of starts or reverse per time frame, say an hour, to allow time to dissipate heat.
IF YOU BOUGHT A SWITCH THAT MATCHES THE MOTOR HP RATING AND VOLTAGE, IT IS LIKELY SIZED LARGE ENOUGH, SIZING IT BY CURRENT ALONE IS LIKELY TOO SMALL
NOW DID YOU WANT CENTER OFF, DIRECTION 1, AND DIRECTION 2?
WITH FOUR TERMINALS YOU ARE GOING TO SWAP DIRECTIONS INSTANTLY CALLED INSTANTLY REVERSING, REQUIRING AN INSTANTLY REVERSING MOTOR, MOST MOTORS NEED TO COME TO REST [POWER OFF] THEN REVERSE.
SOME MOTORS ARE DESIGNED TO INSTANTLY REVERSE, BUT WITH LIMITATIONS ON NUMBER OF STARTS, STOPS, AND REVERSES.
ARE YOU PLANNING TO STOP THE MOTOR IN THE NEW APPLICATION, BY USE OF AN IN LINE OFF SWITCH THEN SWAP DIRECTIONS, THEN REPOWER?
OR DO YOU NEED TO REVERSE INSTANTLY? WITH NO POWER OFF BETWEEN DIRECTIONS?
BECAUSE I DONT KNOW WHAT YOU HAVE AT ALL, JUST GENERAL INFORMATION, i HAVE TO ASSUME ALL COMPONENTS ARE SIZED FOR WHATEVER TYPE OF CONTROL YOU NEED.
HOWEVER MOST WHO KNOW ENOUGH TO MATCH UP CURRENTS, TAKE INTO ACCOUNT INRUSH, AND THE BRUTAL FORCES ON A MOTOR WHEN INSTANTLY REVERSED, KNOW HOW TO WIRE A FOUR POLE REVERSING SWITCH, NOT A SLAM, JUST A FACT, THERE IS NO WIRING DIAGRAM WITH THE SWITCH?
I AM CONCERNED IF WE SWAP DIRECTIONS INSTANTLY WE MAY BURN OUT THE MOTOR, RECTIFIER, SWITCH CONTACTS, OR EVEN WIRES,
INSTANT REVERSING ANY ELECTRIC MOTOR, PRESENTS NOT ONLY THE INRUSH CURRENT PROBLEM VERY OFTEN, BUT VERY CLOSE TOGETHER.
BUT I WILL SUPPLY YOU WITH GENERIC CONNECTIONS, BUT YOU NEED TO MAKE SURE THE INRUSH CURRENT, THE LIMITATIONS ON STOPS AND STARTS IS CONSIDERED,
EXAMPLE, A GARAGE DOOR MOTOR, IF IT IS SENT A SIGNAL WHERE THE CURRENT RISES SO FAST IT ASSUMES THERE IS SOMETHING IN THE PATH OF THE DOOR AND REVERSES.
NOW IT MIGHT DO THAT THREE OR FOUR TIMES, BUT NOT MANY MORE, BECAUSE THE HEAT WOULD BUILD UP AND DESTROY THE MOTOR, DESTROY THE RECTIFIER, DESTROY THE WIRING, SO IT SHUTS DOWN IF THE DOOR KEEPS RUNNING INTO SOMETHING BLOCKING ITS PATH MORE THAN THREE OR FOUR TIMES IN A ROW.
RECTIFIERS MAY BE REFERRED TO AS DIODES
YOU NEED TO READ THE ARTICLE AT THE END OF THIS REPLY
ABOVE SHOWS REVERSING SWITCHES BUT ALL HAVE SIX TERMINALS TO PROVIDE FOR AN OFF PERIOD BETWEEN DIRECTIONS
IN ALL THESE EXAMPLES A FOUR TERMINAL SWITCH DIAGRAM IS NOT PROVIDED, BECAUSE OF THE LACK OF A CENTER OFF, OR POWER OFF MOMENTARY TIME BEFORE CHANGING ROTATION, PLEASE READ ABOVE
BELOW: THIS HAS TO BE A GOOD EXAMPLE OF WHAT SWITCH YOU BOUGHT, IT WOULD INCLUDE SOME SORT OF INTERNAL MOSFET CIRCUIT, OR PWM [PULSE WIDTH MODULATION] BUILT INTO THE SWITCH, IN OTHER WORDS DONE ELECTRONICALLY
IF THIS IS THE TYPE OF SWITCH YOU BOUGHT, THE SWITCH SHOULD HAVE CAME WITH A WIRING DIAGRAM, GRANTED THEY DO A CRAP JOB ANYMORE OF PRESENTING HOW TO WIRE DIAGRAMS, SO MAYBE YOU NEED TO SEND ME THE MODEL NUMBER AND DATA OFF THE SWITCH
IN ANY CASE IT IS NOT A SIMPLE MECHANICAL SWITCHING OF POLARITIES WITH ONLY FOUR TERMINALS,
THESE SWITCHES WITH THE FOUR WIRES IN THE LINK ABOVE, NORMALLY NEED A "CONTROL SIGNAL" TO OPERATE VERSUS A MECHANICAL SWITCH KNOB OR MANUAL TOGGLE ARM
I NEED MORE INFO TO HELP YOU, AND I NEED TO MAKE SURE YOU HAVE A LARGE ENOUGH SWITCH TO HANDLE THE CURRENT AS SMALL AS IT MIGHT BE, IT IS ALL RELATIVE AS I STATED,
NEW LOAD CURRENT, TO WIRE SIZE, TO SWITCH SIZE, TO MOTOR, CAPACITY IN AMPS AT RATED VOLTAGE, IF ONE COMPONENT IS NOT CAPABLE THE WHOLE CIRCUIT WILL FAIL
IF THE LINKS DO YOU NO GOOD, WRITE ME BACK, USE MY PERSONAL EMAIL firstname.lastname@example.org it is faster, but it removes the info for anyone to share so up to you,
I just need more details
The Open/Close switch (SW1) (DPDT Double Pole Double Through)
selects the voltage polarity applied to the motor and thus motor
direction to open or close curtains (drapes).
If the mechanism is not at either of the limits, the Limit Switches
(LS1 & LS2) will be closed. Depending on the position of SW1 and
motor connections, the motor will turn clockwise or anti-clockwise
to open or close the curtains (drapes).
When the curtains (drapes) approach either the final open or closed
positions, an adjustable limit switch catch should open the contacts
of the appropriate limit switch (LS1 or LS2) and stop the current
flow and thus the motor and movement of the curtains (drapes).
At this point the diode across the open limit switch contacts should
be reverse biased and thus not conduct.
If the Open/Close switch (SW1) is switched in the opposite direction
the voltage polarity across the motor would be reversed and the
should now conduct until curtain mechanism moves and the now open
limit switch closes again. The current will continue to flow until
the opposite limit switch is reached opens to interrupt the current
flow and stop the motor. A special switch with a Centre-OFF position
could be used for (SW1) or a separate Power ON/OFF switched (not in
the drawing) will allow the curtains (drapes) to be partly drawn.
The transformer, diodes, fuse and switches should be selected
according to the requirements of the specific motor and curtain
mechanism. Capacitor C1 suppresses the electrical noise generated by
For every installation the power required to move the mechanics
can be different (due to the type of curtains and friction and often
the power supplied to the motor might require some tuning.
During installation and setup the use of a Variac or light dimmer to
slowly increase the power to the circuit is highly recommended.
This allows one to verify the correct setting of the limit switches
and fine-tune the circuit (transformer) voltage. It also assists
the selection of the appropriate resistors for the speed-reduction
switches as the mechanism approaches the limit switches
(see circuit 2).
A transformer with extra taps just below and above the normally
required output voltage, can be quite handy, else an appropriate
dropper resistor can be employed to reduce the power to the motor
The rectified but un-smoothed AC voltage supplies a pulsating DC
voltage and current to the motor that helps to overcome friction
in the curtain drape mechanism (and assists starting) but reduces
the average voltage applied to the motor. The rectified AC voltage
pulses should also be less strenuous to switch contacts than pure
Circuit 2: Curtain (Drape) motor control with automatic stop.
The circuit also includes extra switches to reduce motor speed
just before the end-of-rail limit switch is reached.
This circuit only supplies half-wave power to the motor but
employs a simple SPDT (Single Pole Double Through) switch
for direction control. A higher voltage supply transformer is
however required to compensate.
The full-wave power supply with DPDT switch depicted in circuit 1
could however be used with the rest of the circuit.
Stop1 Slow1 FAST Slow2 Stop2
Left |<_________---------------__________>| Right
--> / / \ \
D3 /<|LS1 /<|LS2 LS3|>\ LS4|>\
SW /o--|>|-| / | / | | \ | \
|--o/ +--+/ |+--+-/ |-+----------+-| \-+--+| \+---|
| o--|<|-| | | | | | | | | |
| D4 +-|>|-+ +-/\/\/-+ +-/\/\/-+ +-|<|-+ |
--- | <-- D1 R1 R2 D2 |
) | Left -------+
)( | __|__
AC )( Transformer Open & Close can be substituted | / DC \
)( for Left & Right C1 === |Motor|
) | | \_____/
) | | |
--- | -------+
| _______ Fuse 3A (see description) |
All diodes should be selected to survive the motor's stall current.
R1 & R2 values are determined by experimentation - should be high
These basic circuits could be used for more than curtains (drapes)
and the pulsed AC lends itself to SCR and Triac control.