Need Help!- 24Vdc Solid State Relay not the same as mechanical relay??

[cjchands]

Hello Guys.
I have this 2 brand new Solid State relays
(Salsar, SSR-10DA)
SSR Relay (SSR-10DA) - China Solid state relay,ssr,relays in Relay & Contactor

which I am currently use to close NO contact with 24Vdc input from CNC controller manual buttons (spindle CW and spindle CCW).
The LED is is lid when push on/off...but the contact (Load Voltage: 24-380VAC) doesn't seem to close......

Question is...this type of solid state is no good to close the contact?? Or am I just having bad Solid State?
Alternatively....mechanical relay works just fine....
I thought it works just the same?

[Al_The_Man]

I see no reason why it shouldn't work?
I assume you are switching the AC to spindle direct, what type of spindle?
how are you achieving the reverse (CW/CCW)?
Al.

[cjchands]

Al,
I was pretty confident that should work too.
I connect the 2 SSR to FWD/REV/COM on the inverter to drive spindle CW/CCW.
Normal relay works. Perhaps just bad solid state relay?

[Al_The_Man]

I am still not clear as to what you are controlling, those particular SSR's are intended to switch an AC load directly.
If you are using them on a VFD type controller using theVFD logic inputs you are using the wrong device, they will not switch the low voltage low impedance input of a VFD.
Al.

[cjchands]

I think you are right.
I am using those LOGIC for the contact VFD, not the load itself. I thought it could be used similarly to the normal relay.

[cjchands]

But I am wondering why can't the logic contact be connected? it is just the contact open/close?

[Al_The_Man]

NO, the SSR has to see a compatible load and voltage type, the CW/CCW inputs are low level logic DC, the SSR's are high voltage AC output type, you may be able to use a low level logic output type such as 24vdc in and low level DC output, but in this case it seems hardly worth using SSR when a small simple mechanical relay would do it.
Al.

[cjchands]

Thanks Al
very clear explanation.