Where's my 24V ???

[fingermcginty]

Troubleshooting a simple circuit today in a PD panel . There is a small 24V power supply on the DIN rail. .It has line voltage on the input and 24V DC on it's outputs across the (-ve) and (+ve) terminals. Schematic says the (+ve) is connected to a fuse and then runs onto the rest of the circuit.
I thought there was a break between (+ve) and the power supply side of the fuse because when i measured between the panel door grounding point and the power supply side of the fuse I wasn't getting 24V DC on the meter. Would I be right in saying the above condition would be true if the power supply wasn't grounded ?

[budm]

Re: Where's my 24V ???

Do you know if the -VE is tied/connected to the panel/chassis?
Pictures of what we are dealing with?
The more info we get the better help you will get.

[fingermcginty]

Re: Where's my 24V ???

Do you know if the -VE is tied/connected to the panel/chassis?

I think that's the problem right there. I was assuming that the -ve is always tied to chassis ground but apparently not.

[fionaan]

Re: Where's my 24V ???

Troubleshooting a simple circuit today in a PD panel . There is a small 24V power supply on the DIN rail. .It has line voltage on the input and 24V DC on it's outputs across the (-ve) and (+ve) terminals. Schematic says the (+ve) is connected to a fuse and then runs onto the rest of the circuit.
I thought there was a break between (+ve) and the power supply side of the fuse because when i measured between the panel door grounding point and the power supply side of the fuse I wasn't getting 24V DC on the meter. Would I be right in saying the above condition would be true if the power supply wasn't grounded ?

i suspect the problem is a simple but large part