Mk V power loss disconnect unit dead

[ash]

Thanks again for the advice. I guess it's to keep me safe rather than the machine. I've re-wired it without the unit and it works again. Thats saved spending 1/3 of what I paid for the whole shopsmith !!!

[terrydowning]

My guess is that this part is either a UK or EU safety requirement. Just a guess though.

[Locmine]

Hi there,

I've got the same problem on my shopsmith and I don't really understand the proposed wiring to bypass the loss disconnect device, do you mean to connect the "hot and return" together and isolate the neutral?

Many thanks
Matt

[DLB]

This device is not found in a U.S. market machine, many of us are in the dark about it. Your use of the terms 'hot, return, and neutral' seems off, I hope the device is not labeled that way. Return and neutral are essentially the same thing for U.S. 120 VAC power. So no, you do not want to connect hot and return together. That would be a short circuit in primary power. I think this device acts as a switch, and what you want to do is connect the input to the switched output to determine if this device is the source of your problem.

I'm thinking JPG missed your post so I'm answering mainly to move this back to the top of the pile. The instructions seem very clear to me, but if I was doing it I would want to confirm my assumptions on the actual hardware.

- David

[dusty]

This device is not found in a U.S. market machine, many of us are in the dark about it. Your use of the terms 'hot, return, and neutral' seems off, I hope the device is not labeled that way. Return and neutral are essentially the same thing for U.S. 120 VAC power. So no, you do not want to connect hot and return together. That would be a short circuit in primary power. I think this device acts as a switch, and what you want to do is connect the input to the switched output to determine if this device is the source of your problem.

I'm thinking JPG missed your post so I'm answering mainly to move this back to the top of the pile. The instructions seem very clear to me, but if I was doing it I would want to confirm my assumptions on the actual hardware.

- David

Go back and read the thread along with the image of the device. This is a relay that opens the the motor hot line whenever the actuating power (relay disengages) is lost. Connecting the two terminals together has the effect of disabling the "disconnect".

[JPG]

This device makes more sense if installed on unattended equipment that would create a hazard if restarted(unattended).

What I am curious about is what/how the internal relay(hot/neutral?) is energized initially.

Is there perhaps an additional manual(mechanical) aspect to this? An internal manually operated switch to 'set' it 'on'?

[RFGuy]

This device makes more sense if installed on unattended equipment that would create a hazard if restarted(unattended).

What I am curious about is what/how the internal relay(hot/neutral?) is energized initially.

Is there perhaps an additional manual(mechanical) aspect to this? An internal manually operated switch to 'set' it 'on'?

Well, this thread piqued my interest so I did a little searching to try to understand the pictured part. I couldn't find anything on the model number "SP-0303-240" or the ATC Diversified Electronics related to this part. However, the relay on top of it is still a referenced part #. If you look up Zettler AZ2100–1A–110DE you will find it is a SPST normally open relay. Unclear if there are more electronics inside of this "power loss disconnect". Presumably this relay just gates the AC input and disengages on a power disruption. If it is as described, is there a reset to clear it when a power loss happens? Or does it just disengage AC power for a specified period of time to protect the operator during a power outage or power glitch?

https://www.azettler.com/pdfs/az2100.pdf

Must be a UK and/or European addition to the Mark V for regulations there. On this UK repair site, they reference checking pass or fail on this "power loss disconnect" device (Check the Euro switch Power Loss disconnect for function PASS FAIL. - see link below).

https://martins-supplies.co.uk/presta/h ... epeat.html

[BuckeyeDennis]

This device makes more sense if installed on unattended equipment that would create a hazard if restarted(unattended).

What I am curious about is what/how the internal relay(hot/neutral?) is energized initially.

Is there perhaps an additional manual(mechanical) aspect to this? An internal manually operated switch to 'set' it 'on'?

Just spitballin' here, but I have a theory.

I'm guessing that the 30 amp switch depicted with dashed lines on the circuit diagram is the internal contact of the "Power Loss Disconnect" (PLD), that the terminal labeled "HOT" is connected to line voltage, and that the block labeled "EQUIPMENT" includes the Mark V and its power switch.

Given these assumptions, the PLD is line-powered, and is capable of interrupting power to the Mark V. It would then be pretty easy for the PLD test the impedence of the Mark V when the line power comes on, prior to closing it's internal contact. In this way, it can determine if the Mark V power switch is on (low impedence) or off (high impedance). If the power switch is on, the PLD can simply keep its internal contact open until it sees the power switch turn off. That would be a fairly simple circuitry.

power loss disconnect larger image.jpg (85.95 KiB) Viewed 8745 times

[dusty]

This device makes more sense if installed on unattended equipment that would create a hazard if restarted(unattended).

What I am curious about is what/how the internal relay(hot/neutral?) is energized initially.

Is there perhaps an additional manual(mechanical) aspect to this? An internal manually operated switch to 'set' it 'on'?

Well, this thread piqued my interest so I did a little searching to try to understand the pictured part. I couldn't find anything on the model number "SP-0303-240" or the ATC Diversified Electronics related to this part. However, the relay on top of it is still a referenced part #. If you look up Zettler AZ2100–1A–110DE you will find it is a SPST normally open relay. Unclear if there are more electronics inside of this "power loss disconnect". Presumably this relay just gates the AC input and disengages on a power disruption. If it is as described, is there a reset to clear it when a power loss happens? Or does it just disengage AC power for a specified period of time to protect the operator during a power outage or power glitch?

https://www.azettler.com/pdfs/az2100.pdf

Must be a UK and/or European addition to the Mark V for regulations there. On this UK repair site, they reference checking pass or fail on this "power loss disconnect" device (Check the Euro switch Power Loss disconnect for function PASS FAIL. - see link below).

https://martins-supplies.co.uk/presta/h ... epeat.html

Yes, but it is available in three different forms. SPST, normally closed and SPDT, normally open. Which one is this?

[RFGuy]

Yes, but it is available in three different forms. SPST, normally closed and SPDT, normally open. Which one is this?

From the datasheet, that part number (AZ2100–1A–110DE) would correspond to the Form A which is a SPST NO relay. It would be a different part number if it was one of the other forms...