Issue wiring a 6-lead single phase motor to an 8-pin control relay

[TwoBlocked]

Sorry, I keep looking at that schematic as a ladder diagram. it's not.



Well, no. Not if the (switched) incoming 120V line was connected neutral to 4 and hot to 3.

-Hal

You would have to switch T1&T3 to 2W and T2&T4 to 512 while leaving T5&T8 where they are. You would be switching the continuously powered run windings instead of the intermittently powered start windings. If all the terminals are switched, the motor does not reverse, you know?

 

[hbiss]

You are right. I was just trying to justify how the coil is connected. Incoming power has nothing to do with that thing. The motor would be powered as usual per the diagram on the motor. The relay only swaps the red and black leads of the motor. Only the contacts are used.

So why the h*** does the coil through the circuit breaker connect to the contacts of the relay??

The way I read the schematic is CR506 a SSR (Solid State Relay), and the symbol shown is a triac that functionally acts as the motor contactor. SSRs do not have a coil as electro-mechanical contactors do and therefore do not have an inductive kickback that can fry some transistors. CR506 is likely to be energized by a DC circuit that could be damaged by inductive kickback.

I really don't think so, not the way it's wired to the contacts like that.

I'm beginning to think that this machine has been bastardized over the years, perhaps having a DC motor. I think the OP needs to do some rewiring, perhaps getting rid of that relay altogether. A simple DPDT relay with it's coil controlled by whatever reverses the machine would do the job. But I don't think he will be able to figure it out.

-Hal

 

[TwoBlocked]

...
So why the h*** does the coil through the circuit breaker connect to the contacts of the relay??

...

When you say "the coil through the circuit breaker" are you referring to CR506?

 

[hbiss]

Yes. There is a 10A CB fed from someplace on sheet 1 that in turn feeds one side of the coil (CR506). The other side of the coil connects to the motor contacts and terminals 1&3. And don't you think that a10A circuit breaker is a bit much just to power the coil of a relay?

I do see now on the relay drawing "1/4 HP, 1 ph, 115VAC, 5A, 1725 RPM, 50/60Hz" so scratch my assumption about their possibly being a DC motor.

We are not getting the entire picture.

-Hal

 

[TwoBlocked]

Yes. There is a 10A CB fed from someplace on sheet 1 that in turn feeds one side of the coil (CR506). The other side of the coil connects to the motor contacts and terminals 1&3. And don't you think that a10A circuit breaker is a bit much just to power the coil of a relay?

I do see now on the relay drawing "1/4 HP, 1 ph, 115VAC, 5A, 1725 RPM, 50/60Hz" so scratch my assumption about their possibly being a DC motor.

We are not getting the entire picture.

-Hal

Here is a partial repeat of post #36. The symbol is not for the coil of a relay. It functions as the contacts of a relay. And no, the 10 amp breaker is ok. NEC tables list the FLA at 5.8 amps and the max inverse time breaker is 250%.

The way I read the schematic is CR506 a SSR (Solid State Relay), and the symbol shown is a triac that functionally acts as the motor contactor. SSRs do not have a coil as electro-mechanical contactors do and therefore do not have an inductive kickback that can fry some transistors. CR506 is likely to be energized by a DC circuit that could be damaged by inductive kickback.

 

[hbiss]

The way I read the schematic is CR506 a SSR (Solid State Relay), and the symbol shown is a triac that functionally acts as the motor contactor.

I see what you are getting at but a triac would have a third gate lead to turn it on and off.

-Hal

 

[TwoBlocked]

I see what you are getting at but a triac would have a third gate lead to turn it on and off.

-Hal

Yes, but probably 2 leads for a DC input. And that would be on another sheet with the circuit that starts and stops the motor.

 

[hbiss]

Yes, but probably 2 leads for a DC input.

Doesn't work that way.

-Hal

 

[kwired]

You would have to switch T1&T3 to 2W and T2&T4 to 512 while leaving T5&T8 where they are. You would be switching the continuously powered run windings instead of the intermittently powered start windings. If all the terminals are switched, the motor does not reverse, you know?

Kind of sort of doesn't matter which ones you physically switch, the motor will still run the opposite direction. What matters is the relation ship between T1/T3 to 5 or 8 and T2/T4 to 5 or 8. Only reason to prefer swapping 5 and 8 through the relay may be because of contact rating not being enough to handle the main winding vs the aux winding.

 

[TwoBlocked]

Doesn't work that way.

-Hal

I expect it would be something like this. OK, back to back SCRs instead of the triac symbol that was shown.

 

[LarryFine]

AC solid-state relays don't require a turn-off circuit, only DC ones do.

 

[newtonwb]

Maybe this will help? This is how I see it should done as mentioned in a previous post.
Looks to me like:
CR506 = On / Off
CR507 = Forward / Reverse

 

[Namcy]

Maybe this will help? This is how I see it should done as mentioned in a previous post.
Looks to me like:
CR506 = On / Off
CR507 = Forward / Reverse



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Thank you very much for the detailed and clear wiring diagram. I do greatly and really appreciate the time and effort you put in.