Need some wiring help with monitor stand and surge protector

[vanderk]

Hi. I recently pick-up a monitor stand (Porta Micro Mate) made in the 80s by SOS computers that was designed for the Commodore 64 and Kaypro computer. It is very functional but the surge protector and switches were not wired at all (appears someone disassembled the stand at some point and unplugged the wiring at the surge protector circuit). I'm not entirely sure how to plug in the hot, neutral, and ground spade connectors in combination with the Varistor on the board.

- There are 5 hot, 5 neutral, and 5 ground wires (2 switches, 2 outlets, and one AC plug)
- 15 spade connectors are on the board; connectors are connected in pairs and groups of three and some of these pairs/groups are also connected via traces
- Two screw holes are connected to a group of three spade connectors in the center
- Two pair of spade connectors are "floating" and simply soldered to the board

Can anyone please help me with this puzzle? I am a ham operator and used to working around AC, DC, and HV wiring; but this one has me a little stumped. Thank you!

The Varistor goes to a pair of spade connectors on one side and three spade connector on the opposite side.

P.S. Pushing the "computer" or "monitor" button shorts neutral and hot (I believe these are wired correctly). I am assuming the two screw holes and spades connected via traces to the holes go to ground, but I wind up having two extra ground wires not connected.

 

[westom]

MOVs do not appear to have the always required thermal fused (typically rated less than one amp). An original owner may have disconnected those MOVs to avert a house fire. If thermal fuses do not exist, you are strongly advised to leaven MOVs disconnected.

 

[vanderk]

Another detail... for both switches, black is "line", white is "load", and green is "line-lite".

 

[vanderk]

Let me preface: please don't try this at home!

Okay, I figured it out!!! I had to draw a diagram to figure this mess out. The wiring color for the switches was throwing me off--I had to recall that line is "in" and load is "out". The switches' line-lite (green color in picture) goes to neutral and on the same strip as the AC neutral, so all the neutrals bond together with the two neutral lights (which are actually using green wires with yellow dashes). Blacks (hots) are all connected. The loads on the switches used white wiring, but they are really hot (this explains the black dashes on the white wires). Switches go before the outlets in the circuit; grounds are all connected and bond to the cabinet.

Anyway, it works and all checked out with my VM (plus I haven't burned my house down).



Here is a picture of the stand from "Word Processing on the Kaypro". My stand has been disassembled for powder coating.

 

[Chuck(G)]

I'm a little confused over your use of the word "neutral". All green wires are ground and should be bonded to the chassis. Whites are the "neutral" side of the line supply. In no case should either blade of the AC plug show any continuity with the metal chassis.

If you've done that, then you should be fine.

 

[vanderk]

Yes, it is confusing. The light neutral for the switch illumination used a green wire with yellow stripes--this actually goes to neutral. I was confused by the color scheme because ground should not go to neutral as you noted! Perhaps they should have used a white wire coming out of the switch light's neutral.

 

[Chuck(G)]

Well, I don't know--I'm used to switches with spade lugs on the body, so the color can be anything. I suppose that blue might have been a better choice.