Power supply to Protect PLC

Hello Everyone,

I have in an electrical panel a simple 220VAC to 24VDC power supply (as shown on the picture bellow)

can this type of power supplies protect the PLC from Over/Under Voltages coming from the grid ?

Thanks in advance for your answers.

We can't answer because we don't even know if the power supply is powering the PLC, or how it powers the PLC. Then you would have to say how much under or over voltage you are hoping to protect against.

I can say that the power supply is 100-240V, so it should work down to 100V. Most power supplies will have some allowance for an over voltage, but I have no way to know how much.

BryanG said:

We can't answer because we don't even know if the power supply is powering the PLC, or how it powers the PLC. Then you would have to say how much under or over voltage you are hoping to protect against.

Click to expand...

The PLC is powered directly by 24VDC coming from this power supply.

We don't know how much Under/Over voltage this PLC can tolerate, but lets say it would be 10%

BryanG said:

I can say that the power supply is 100-240V, so it should work down to 100V. Most power supplies will have some allowance for an over voltage, but I have no way to know how much.

Click to expand...

This power supply has some tolerance for Under/Over voltage but it is not a stabilized power supply I suppose, so It does not deliver a constant output. Which means that in case of high over voltage in the input, we will have an over voltage in the output.

That's not how it works.

If the PSU has 240V going in, it will have 24V going out.

If the PSU has 100V going in, it will still have 24V going out, but more current on the input.

Check the PSU for what tolerance over voltage it can take, but if it goes to 250 as an example, this does not correlate to a higher output voltage.

If this is a very sensitive PLC and needs protection, I would add a 24V DIN rail mount UPS feeding it.

Replace it with something from a reputable manuf. with known over/under tolerances. Weidmuller do some good PSU.


https://www.weidmuller.com/en/products/electronics/power_supplies/index.jsp

You

I used these transformers in past for sensitive components like plc.

https://solahevidutysales.com/cvs_hardwired_series_power_conditioner.htm

this would be something you could mount on outside of enclosure if your power supply backup will not work.

+1 on the sola heviduty conditioners.