Electric Motors/Delco A8855 wiring
QUESTION: I have an old Delco A8855 1/2 hp motor with no cover plate, on a 10 inch band saw.
the motor is wired with a 220 vac plug, and marked as 110/220 v, when turn on the motor lacks speed and power. I checked the electrical connections and here is what I found.
if you remove the ground wire the motor doesn't run.
there are 5 connections in the motor 2 are marked L and TL the 220 v are across these.
in the center there is a red button. wire 1 is red the rest are black.(see picture)
the number wires and location are as follows.
4,5,1 TL(3, line)
could you tell me the correct way to wire this motor for 220.
ANSWER: Randy let me make sure I understand what is going on, 5 motor connections, 3 incoming two hots and an EARTH GROUND, it is still hard to see exactly although it is well done photo,
It almost appears if 451 are bundled that the lines are on where the 4 and 1 should be,
If there are three incoming with two hot and one earth earth goes to the frame period,
For a high voltage or 220 connection line should be to 1 and 4 2-3-5 should make up an electrically connected and isolated series connection, normally there are six leads if reversible swapping 5 and 8 to reverse,
there is some reason they put a TL and T one of them must have the other end of 5 the start winding on it,
So low voltage or 110 would be 1-3-5 to either TL or T [sorry Delco did a ton of oem motors especially for some kind of vehicle related application] with 2-4 to the other line but I cannot say what or which [TL or L has the other end of the start winding on it],
The normal idea is the start winding is always 110 volts to get there at the high 220 connection they center tap the other end of the start in this case 5 with the series connection of 2-3
The internal connections can be backwards also some manufactures use 1-2 then 3-4 as each half of the run, so you can put it in parallel or series, but some use 1-3 and 2-4 as each half, so two issues that need to be dealt with,
Because 1-3 or 24 r however they labeled the halves of the run you could actually use 3 and 2 as lines as long as they were kept in the same relationship,
That I know sounds confusing but the motor should have two identical sets of wire for the run windings, so using the NEMA convention of 1 and 4 really is just that a convention to keep things the same, but if you think about it is just piece of wire wrapped around iron and whatever end you use is the same thing, but lets stick with 1 and 4 being the lines, and then put 23 together with the 5 and isolate,
An earth ground never goes to a winding, this is a point of confusion as many are familiar with using the neutral on appliances as the center now days they use four wires a dedicated earth and the neutral on appliances, but motors are different,
So if 2 is connected to ground it and even though it seems they were connecting this thing backwards of NEMA it would stop
The red button is an internal bi metal thermal, if it gets hot the metal expands and opens the circuit and unloading the button, once it cools the red button can be reset and off you go, these old buried thermals do get weak and can cause lots of problems often we simply jump them out, internally,
But for now try 1 to a hot 4 to a hot, earth to frame and 2-3-5 electrically connected and isolated,
If you put one on TL and nothing happens first try swapping the one on TL Either 1 or 4 with each other as described it probably indicates one of them has the other end of 5 the start circuit on it, if you put both ends of the start on one line you have nothing no start circuit, that would make the motor maybe try to start but roll very slowly and might kick off with a careful spin prior to energizing, but be careful, the most important of all of this is the earth ground does not go to a winding only to chassis/frame try that and let me know if you are successful, they may have had it wound only knew to use one end of each run, there are a dozen reasons for this but lets hope it is simply misconnected, let me know either way
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QUESTION: thank you for the info.
I took off the wires and checked them.
1 and 3 are one coil, 2 and 4 the other.
5 is one side of the capacitor, the other side of the capacitor is connected to the top 2 studs.
(wire 2 and ground).
all other studs are isolated.
I moved the line voltage from the center stud attached it to where the ground was. moved the ground to the
motor housing. checked all the wires make sure there were no unwanted shorts.
motor is now working fine and turning the correct direction, now I need pulleys to so the blade down.
Hello Randy, I see another reply, but I see nothing new, you were going after pulleys which is how we left it, need something else? If so I have read this four times and see nothing else in the form of a question did you need help with pulley sizing?
That can be tricky, the ratio of torque from the motor to the needed torque on the load can overload the motor, if the pulley ratios are way off, along with the belt tension, belts should not be so tight you can you could do a back flip off them, too much radial load,
that is about it in general if you need something else let me know,