Connections to change 110/220V 1 HP motor, back to 110V

[Bob338]

I have this old motor driving an air compressor. The motor is convertible to either voltage and is presently running 220V. I want to reconnect the terminals to run on 110V. The manufacturer, Howard Industries in Arkansas, refers to instructions on name plate. The instructions on the name plate only show diagram of four terminals vertically with the top designated "L1" and the bottom "L2". The diagram shows wiring "orange 13" to be connected to the second terminal from the bottom, for "high voltage". It also shows "white 12" connected to this second terminal.

For "low voltage" it shows "white 12" connected to the bottom (L2)terminal and "orange 13" connected to the third terminal from the bottom. Those two terminals now have connection to the windings.

All wiring is black except for the one white wire. The two lower terminals have double spade connections, the 3rd and 4th are single spade connections. Two black wires presumably leading to the windings are connected to the second and terminals presently, but have to be moved to enable the connections shown by the manufacturer for "low voltage". Where should the wiring for the windings be connected when removed to accommodate the power? One has black paint on the connector. Help!!

 

[jbartos]

Suggestion: It appears that the Howard Industries does not offer the electrical motors at the following web site:

http://www.howard-ind.com/default.asp

It may be a good idea to inquire about a tech support for the motor you have at the posted link.
There were some acquisitions that affected the Howard Industries motor manufacturing. See

http://www.dcmcorp.com/

for details.
Or perhaps

http://www.eadmotors.com/products.asp?sel=AC_Induction_Motors_Desc.static

 

[SteveKW]

Start over again. Starting from the top terminal describe how the motor is connected NOW for 220. Where the two power leads are and where the other leads are.

Also, on the motor nameplate... what are the amps of the motor?

 

[Bob338]

Thanks. The top terminal (L1) is unconnected. The spade looks like it may have had a lead to it at one time.

The second terminal from the top has a single spade connection to which is connect a black power lead.

The third terminal has a double spade connection to which presently the two leads for the coils are connected.

The bottom or fourth terminal (L2) also has a double spade connection to which presently the white power lead is connected.

According to the name plate BOTH power leads should be connected to the third terminal with the double spade connections where the coils are both connected. If I remove the connections for the windings to connect the powder to this third terminal per the name plate, I'll need to connect those leads to two of the three remaining terminals. Which ones? One of those leads from the windings has black paint on the connector. Both are black wires and the same otherwise.

 

[spector]

It's ok, you can figure it out.

First unplug the motor and install a regular 3 prong 110 V plug on the pigtail. The pigtail should contain 3 conductors. 1 white, 1 black and one green. Black is hot, white is neutral and green is ground. If your pigtail isn't configured that way, go buy one with the plug aleady installed.

Your motor has two sets of 120 V windings. Thay can be connected either in series or parallel.

Connected for 240V they are in series.

Connected for 120 V they are parallel.

So take your VOM and use it to identify the leads for the 2 windings.

For parallel 120 V, take one side of each winding and connect it to black. Connect the other sides to white. Connect the green to ground and you are thru. You can use the spade connectors and double lugs on the board or you can wire nut it all together.

Good luck

 

[jbartos]

Suggestion: If it is a single phase motor, there might be a starting winding.

 

[busbar]

Possibly another course would be removing the motor and carting it to a motor repair shop. They should be able to reconnect the motor and no-load run test it for a reasonable fee.

 

[SteveKW]

"Thanks. The top terminal (L1) is unconnected. The spade looks like it may have had a lead to it at one time."
The BLACK power lead should be here, regardless of voltage...on L1, not on the second terminal as you describe!


"The second terminal from the top has a single spade connection to which is connect a black power lead."
This is where it goes all awry ... an internal lead from the motor should go here for a 220 V connection!


The third terminal has a double spade connection to which presently the two leads for the coils are connected.
Sounds correct for 220V!

The bottom or fourth terminal (L 2) also has a double spade connection to which presently the white power lead is connected.
The white lead stays here for 110.

According to the name plate BOTH power leads should be connected to the third terminal with the double spade connections where the coils are both connected. If I remove the connections for the windings to connect the powder to this third terminal per the name plate, I'll need to connect those leads to two of the three remaining terminals. Which ones? One of those leads from the windings has black paint on the connector. Both are black wires and the same otherwise.


Typically...
When the black power lead goes to L1 as it should... L1 will have continuity to only ONE of the leads on post 3 and a lead I think you are missing that should have been on post 2. The lead on post 3 that had continuity to L1 is then lowered to the L2 post for low voltage. What we are missing is the lead to post 2 which currently has the black power lead on it! That missing lead then would have also been lowered one notch down to post 3. I suspect this motor has had some problems and someone rewired it to make it work. I suggest you do as Busbar says and take it to a good electric motor repair shop!