Cinch Jones Plugs 4 pins Replacement for Bell Howell 8D655 16MM Projector.

[Bank Vichyothin]

I recently acquired a Bell & Howell 8D655 16MM projector, but it didn’t come with a power cable. As a result, I need to connect the Cinch Jones 4-pin plug to the projector myself. However, I’m unsure how to properly wire the Live and Neutral connections.

Could anyone knowledgeable guide me so I can solder the wires correctly to the terminals on the Jones Plug? The power cord I have prepared does not include a Ground wire. My guess is that pin 14 connects to Live and pin 16 connects to Neutral, but I’m not sure at all.

Thanks

[Steve Klare]

Hi Bank,

A general rule of thumb is that "Live" is the line that runs straight to the main fuse. If you connected Neutral to the fuse and "Live" ends up shorted to the chassis, there would be no main fuse in the way and it would be up to the fuse or circuit breaker in your house wiring (usually multiples of Amps higher) to stop the short, and if the wiring of the projector and power cord can't carry that much current, the thing could burst into flames and maybe take the house down.

The main fuse is sized to be the first thing to blow, within the capacities of all the machine's wiring.

I very much recommend you ground the chassis if at all possible: it could literally save your life. Please see if there is a green wire running from one of the connector pins to a connection to chassis: this is the one you need to connect to a third prong on the power cord.

My guess is it's going to be that one circular post that's sticking out in the middle: the ground connection is supposed to be the first thing to connect and the last to disconnect when you plug/unplug.

[Tom Dennis]

I offer this info taken from SMALL FILM FORMAT FORUM and posted by Maurice Leakey [r.i.p.]

pin no. 13 ----EARTH pin no. 14 ----- NEUTRAL pin no.. 15 -----spare pin no. 16------LIVE

He also notes that if using a B/H CHANGEOVER UNIT both pins no. 15 and 16 were live as one went to the amp and motor the other direct to the mains voltage lamp, this giving switching between 2 lamps

[Tom Dennis]

P.S.
The pin notations above are from my notes from past experience, Maurice in his post lists both pins 15 and 16 are live

[Bank Vichyothin]

Steve Klare Thanks to you Steve, I cannot agree with you more on the safety issue. I checked the plugging unit and saw the green wire running from one of the pins to the chassis. I think I will now have to change to 3 cores power cable.

[Bank Vichyothin]

Tom Dennis Thanks Tom, it is really helpful to me. I tested the wires on pin no.16 --- Live and pin no.15 as Neutral. It works, my multimeter in continuity mode doesn't find a closed circuit. 😀😀😀

[Steve Klare]

Please do!

The fuse and chassis ground work together.

Let's say some internal wire connected to the "Hot" side came loose and touched the chassis of the machine. Without the chassis grounded, the chassis and anything metal connected to would now be at line voltage, and if you touched it, so would you! All you'd need to get electrocuted is touch something else that is grounded.

-but with the chassis grounded, as soon as that loose wire touched it, there would be a brief spark, the fuse would blow, and the chassis (-and you!) would stay down at zero volts: right where you belong!

There are a lot of wonderful old projectors out there with metal cases and two prong plugs. I have a couple myself. I enjoy running them here and there, but I always feel a little bit like I'm messing around with fireworks!

-"It's probably safe!"

Maybe the best one I know is my In-Laws' ancient slide projector (1950s...)
There is an upper housing that is metal and there is only a two-prong plug!
-but the best part is the base that is made of wood!
So, we have a potential shock hazard that went to the head of the class by adding combustibles and becoming a fire-hazard too!

(-all it needed was a concealed vial of poison!)