I Need relay help??

[Rocker4x4]

I thought I was doing this right, Thinking I remember seeing this done this way, but I must be doing something wrong or bought the wrong relay. I'm trying to turn 120v motor on using a 12v push button. I wired this up on the bench to test, and its not working like it should.

See drawing, (sorry for poor drawing, was in hurry) When I push the 12v button is has no effect on terminal 1 on the relay. Terminal 1 is staying hot (120v), pushing the 12v button does nothing but turn light on the relay. What am I doing wrong or missing here?
Here is link to relay i'm using https://www.automationdirect.com/adc/Shopping/Catalog/Relays_-z-_Timers/Solid_State_Relays/Panel_Mount_Relays,_Hockey_Puck_Style,10A_-_75A_(AD-SSR6_Series)/AD-SSR640-DC-280A
See attached drawling

 

[American Locomotive]

The only thing I can think of is to try switching the 120 vac wires so the line is on pin 1 and the load is on pin 2. If that still doesn't work, the SSR might be bad. Does the load turn on as soon as you apply power, before you even push the button?

If the LED comes on, the SSR should be on, if the light is off, the SSR should be off.

 

[LXCam]

Try changing polarity for your switch input. They are polarity sensitive.

 

[BillK]

It looks like you have it wired properly.

Are you sure the motor is good ?

Try disconnecting the motor and putting an ohm meter between pins 1 and 2. It should show "0" ohms when you push the button but I am not certain with it being a solid state type of relay.

Don't discount the possibility of a bad relay.

 

[Rocker4x4]

I changed polarity, no luck. I change terminal 1 and 2 on relay block, no good. The motor I don't have wired up yet, I've just been using a volt meter to check the load side (1&2) terminals on the relay. Yes, as soon as I apply 120v to ether one side 1 or 2 on relay, it instantly makes other side hot??
So I pulled the 120v wire off relay and left the 12v, I check with ohms with digital meter, (that's all I have). I'm not very good at understanding ohms, I know its resistance but I get confused on how its measured or what it should be, so here are the reading I got, can you clear this up for me?
12v NOT PUSHED= 18 m ohms
12v PUSHED= 2 k ohms
help me understand k - m ohms?, this meaning milliohms and kilo ohms??

So it does look like what I'm trying to do is right? Looks like I've got it wired right? What about the relay, is this the right one for what I'm trying to do? They have many to chose from and thought I picked the right one but I did second guess myself.

 

[AntonLargiader]

Try it with some kind of load, like a light bulb.

 

[Tim65GT]

I agree with Anton. Wire up a temporary load and try it.

 

[Rocker4x4]

Well fellas that did the trick, wired a temp light bulb up,, works perfect!! Guess my fault for being lazy and not wiring it all up to try, just thought I could bench test it this way. I guess the relay needed the resistance of something in order to work? I'm kinda happy with myself I was able to accomplish this myself and order the right stuff, Thanks again for the help, now I know. and this is how I learn haha

 

[Falcon67]

For checking continuity with a meter, just set it on an ohms scale and touch the leads together. It should read some number, rather than float. Doesn't matter what number. Expect the same reading when checking a piece of wire or your relay contacts when energized. An analog meter is nicer for this actually because you can just watch the meter swing.

 

[ard]

An FYI.. K=kilo M=Million
So 4K Ohms is 4000 ohms

8 Mohms is 8 million ohms. In this case M = mega..not 'milli'.

In this case reading ohms is pointless, you just want continuity (i.e. 'Connected' or 'not connected'.

Many meters have a tone as well, use that- not numbers.

 

[iron block]

The AD-SSR640-DC-280A spec sheet shows the minimum load current as 250 milliamps.

A typical DMM that is trying to measure ohms will apply a much smaller current to the unknown.

A Fluke 80-series meter, for example, has a maximum current of 1.0 mA for low resistance measurements.

So the thyristor inside the solid-state relay is barely getting enough juice to turn on, and that makes it look like a high resistance to the DMM -- which is why you saw 2 Kohms when the relay was on.

Then when you put a real load on the relay, it got enough current to be happy so it worked as expected.

Rocker -- one other thing to be aware of is that this relay is a general-purpose type not rated for motor horsepower. Crydom has a good application note describing how to handle motor loads. Bottom line is that a 40 Amp general purpose relay can handle a 9 A FLA nameplate motor.

www.crydom.com/en/tech/white-papers/ac_mc_whitepaper.pdf

 

[cgrutt]

I had same issue with SSR last year. Wired correctly but didn't appear to be working without load. Live and learn! Glad you got it sorted out.

 

[Rocker4x4]

The AD-SSR640-DC-280A spec sheet shows the minimum load current as 250 milliamps.

A typical DMM that is trying to measure ohms will apply a much smaller current to the unknown.

A Fluke 80-series meter, for example, has a maximum current of 1.0 mA for low resistance measurements.

So the thyristor inside the solid-state relay is barely getting enough juice to turn on, and that makes it look like a high resistance to the DMM -- which is why you saw 2 Kohms when the relay was on.

Then when you put a real load on the relay, it got enough current to be happy so it worked as expected.

Rocker -- one other thing to be aware of is that this relay is a general-purpose type not rated for motor horsepower. Crydom has a good application note describing how to handle motor loads. Bottom line is that a 40 Amp general purpose relay can handle a 9 A FLA nameplate motor.

www.crydom.com/en/tech/white-papers/ac_mc_whitepaper.pdf

That's not what I needed to hear, lol. So I still may have a problem using this relay for this motor then? The Motor says 15A. I haven't checked it with meter to see what start up or working amps are. I just figured 40amp relay would maybe handle 80% of FLA so I could run about 32amps on it.. being it was 15A I thought I was ok. So your thinking I need a 75amp relay?

The motor HP shows 1.8kw or (2.41hp) , The square D slide chart (I live by)I have shows 120v-single phs- 28FLA- 10ga wire THHN.
Heres a 75a one I think is the same just higher amp rating?
https://www.automationdirect.com/adc/Shopping/Catalog/Relays_-z-_Timers/Solid_State_Relays/Panel_Mount_Relays,_Hockey_Puck_Style,10A_-_75A_(AD-SSR6_Series)/AD-SSR675-DC-280A

 

[iron block]

The motor HP shows 1.8kw or (2.41hp) , The square D slide chart (I live by)I have shows 120v-single phs- 28FLA- 10ga wire THHN.

Looks like 28FLA requires a 125 Amp relay. See Table 2 in that Crydom white paper.

Also, Crydom recommends a random-start rather than zero-cross type of relay. Here is one that meets both specs: http://www.mouser.com/ProductDetail/Crydom/D24125-10/?qs=sGAEpiMZZMtq49AUx5G3778uEJUSSwFqo0QRAUPH7Zo%3d

$100. Ouch.

Any chance you could find a used electro-mechanical contactor to salvage somewhere instead of buying a new solid-state relay?

 

[MBfreak]

"Alternative fact"
Quote from post above:
Milli would be millionth
Unquote.
Accepted facts
Milli is 1/1000 ( 1*10>-3)
Micro is 1/1000000 ( 1*10>-6)

Working with electrical calculations since many years has made me **** regarding figures. Sorry, but that is my affliction.

Ola

 

[LS6 Tommy]

"Alternative fact"
Quote from post above:
Milli would be millionth
Unquote.
Accepted facts
Milli is 1/1000 ( 1*10>-3)
Micro is 1/1000000 ( 1*10>-6)

Working with electrical calculations since many years has made me **** regarding figures. Sorry, but that is my affliction.

Ola

So, what is the scientific prefix for a bintillion?

Tommy

 

[MBfreak]

LS6
Maybe your question about the scientific prefix for a bintillion is better directed to the alternative fact jugglers.
I a sure they have a good answer. They seem to know it all and doing well.

As for me, I´ll stick to the factual facts. Have never dealt with figures smaller that "atto" , ie 10>-18.

Ola

 

[Rocker4x4]

it may be better if I just use a contactor. I have a place near by that sells used electrical stuff, I can prob get one there cheap. I was just trying to get by without using one. but I guess its no big deal to use one. I guess I could use the relay I have to send 110 over to pull the contactor in right?

 

[Alchymist]

Not to be a parade dampener, but if using SS relays for inductive loads, google "snubber circuits".

 

[rburke65]

What he said......

 

[Trey T]

It looks right to me. The only concern is that if they sent you the AC coil version instead of the one you linked. Can you confirm that it is the DC coil?