Selector Switch contact blocks question

PJ was kind enough to get me a wiring diagram before Christmas for my rig. I am upgrading from a simple DPDT toggle switch controlled panel to three way selector switches with 22mm indicator lights to denote bcs control, manual control.

That said, these switches are new to me, and since it has taken me this long to actually have funds to upgrade my panel I forget what PJ told me about these switches.

Basically, based on the diagram below, I believe I need three NO contact blocks. Basically each triangular sets of contacts (i.e 1,2, and 3; 4,5, and 6, etc) denote one NO contact block. Can someone confirm this thinking for me?

I have the money and want to pull the trigger on these switches so I can actually get my upgraded started! Thanks!

cyberbackpacker said:

PJ was kind enough to get me a wiring diagram before Christmas for my rig. I am upgrading from a simple DPDT toggle switch controlled panel to three way selector switches with 22mm indicator lights to denote bcs control, manual control, in addition to "on".

That said, these switches are new to me, and since it has taken me this long to actually have funds to upgrade my panel I forget what PJ told me about these switches.

Basically, based on the diagram below, I believe I need three NO contact blocks. Basically each triangular sets of contacts (i.e 1,2, and 3; 4,5, and 6, etc) denote one NO contact block. Can someone confirm this thinking for me?

I have the money and want to pull the trigger on these switches so I can actually get my upgraded started! Thanks!

Click to expand...

Depends on the kind of selector you're using. With an on-off-on switch like most of us who are using them for element selectors, you'd need four. One NO for each of the "on" positions, and two NCs in series stacked on the NOs to turn the center position of the switch into a 3rd "on". When the switch is in the center position, both NCs will be closed to allow current to flow. In that configuration, there is no "off" position.

If you can find a selector that is an on-on-on type, then you would need 3 NOs.

Got a vendor/part number for what you're going to use?

Actually, hold up a sec. Do you really mean Manual - On - AutoBCS? That doesn't make much sense on 2nd thought, as the manual and on positions are identical.

The partial screenshot you've got appears to be from one of PJ's drawings that is wired up to be a Manual - Off - AutoBCS, which is what I think you actually want.

He shows it wired as a 3PDT (3 poles, 2 connected positions with a center off) selector switch. Each of those triangular sections is a single pole dual-throw with a center off position.

If you're using a 22.5mm selector switch, it gets a little tricky, because a simple NO or an NC block is really a single pole, single-throw device. Two NO blocks with a common feed coming into the input side of each block, with separate wires coming out of each block to either side is the equivalent. So, you would need 6 NO blocks, 3 on each side. Depending on your switch vendor, you can get 2NO blocks which take up less space and cost less than 2 stacked NO blocks. If you're using the cheaper switches from Automation Direct like a lot of us do, then you would be stacking 3 NOs on each side (1-2-3 = 1 pair, 4-5-6 another pair, 7-8-9 the last pair). Plan for a deep control box.

I don't have a pretty schematic library, but here's how I'd do it with the 6 NOs, referencing the numbers in PJ's diagram:

2, 5, and 8 are actually the same side of a pair of NOs. So, attach 2 NO blocks to the actuator, run a jumper between the terminals on one side of the two blocks, and connect the appropriate wire in. On the drawing I'm looking at (http://www.pjmuth.org/beerstuff/images/BCS-460-wiring-2-4-c.jpg), 2 and 5 go to the coil on a contactor. 8 goes to the Control+ on an SSR.

3, 6, and 9 are all going to be the opposing contact in one stack of NOs. 9 goes to your +5VDC, so it's manual control. 6 just gets 110V from the breaker, and 3 goes to the colored light for manual mode.

1, 4, and 7 would be if you flip the switch the other way. 7 goes to a Discrete Out on the BCS for auto control, 4 goes to the 110V line, and 1 goes to the colored light for auto mode.

Okay, I am just going to post the whole diagram to hopefully help my first post make more sense (based on a diagram from PJ). The switches for the elements are intended to indeed be a manual on- off- AutoBCS.

The additional "on" (or "active" might be a better descriptor) indicator light I alluded to is not controlled by the switch; it is after the contactor and it shows that the element is actually firing. The other lights controlled by the switch merely tell me how it is being controlled.

Does the below image help make things clearer?

Right now I am not concerned on how to physically wire them (yet) but just how many contact blocks do I need to order for my shown switches.

Oh, and I am looking to order these switches:

http://www.ebay.com/itm/300619324995?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

And these contact blocks:

http://www.ebay.com/itm/300674161776?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Thanks for the help, it is appreciated!

Ok, good. Looks like we cleared things up.

It looks like each switch comes with 2 NO contact blocks if I'm reading the description right. In that case, you'd need 4 additional blocks per switch (8 total), so a single order of 10 blocks from the 2nd link would be enough for the element switches.

If you're using the same switch for the three switches on the bottom of the diagram, each of those switches needs 4 contact blocks. Again, assuming the switch comes with 2, you'd need 6 additional.

So, in total, you'd need 5 switches and 24 blocks. If each switch comes with 2, then you need 14 additional blocks (2 10-packs).