Multiplexer or relays?

[Don B.]

Is the Idx multiplexer as reliable as mechanical relays? I’ve never used them but I’m rebuilding my low pressure systems and they all use mechanical relays to the motor contactor to isolate the bays. I think I’ve only changed out one or two relays in 27 years, or at least that’s all I can remember, there might’ve been a couple of more . I just rarely ever have a problem with a relay. I like the idea of a simple multiplexer without a box full of relays and jumper wires. But the relays are very reliable. I’ve got four systems that use it, spot free, presoak, soap and wax. Yes, I use a pressurized soap and wax system. I pressure feed hot and cold water to my high-pressure pumps with two dema solenoids, and directly inject soap and wax into the incoming water line with a pro con pump at 100 psi for each. You have to set your pump pressure about 15 or 20 psi higher than your incoming water pressure. I rarely see anybody use this type of system. But personally that’s the only way I’ll ever do it. When I first got into the car wash business, I used individual float tanks and suction fed my soap and wax. Constantly fighting float valves, check valves, etc. I didn’t like that system. Then I decided to pressure feed my pumps with zero pressure regulators and dema 203 injectors, etc. I had a lot trouble with the regulators, was constantly rebuilding them, never could keep it consistent. Then many years ago a carwash owner told me about pressure feeding your soap and wax with Procon pumps. Well, I converted it over to that. That’s the only way I’ll do it now! Once in a great while I have to change out a Procon pump, and on rare occasions, a motor! It’s been very consistent for many years now. But anyhow, I was thinking about going with the multiplexer would like opinions on people that have used them a long time.
Thanks!

 

[MEP001]

I've replaced IDX multiplexers before. They aren't perfect, but they are pretty reliable. I prefer relays. I strongly recommend a time delay relay for each pump controlled by a bank of isolation relays. People turning quickly through the functions is what causes relays with an inductive load to fail, usually arcing the contacts and fusing them closed.

I know you said you aren't interested in changing your soap and wax supply method, but if you ever think you might I can give you a list of the check valves and solenoids that are near 100% reliable in my experience. I've remodeled a couple washes with the zero pressure regulators, seemed like a good idea at the time since they were both having severe manifold washout and seal failure issues because of having a tiny open tank for each pump, and eliminating the tank in favor of the zero pressure regulators did solve the other maintenance issues, but like you they both had issues with the regulators failing. If only they'd make the cartridge out of stainless steel...

 

[Don B.]

I've replaced IDX multiplexers before. They aren't perfect, but they are pretty reliable. I prefer relays. I strongly recommend a time delay relay for each pump controlled by a bank of isolation relays. People turning quickly through the functions is what causes relays with an inductive load to fail, usually arcing the contacts and fusing them closed.

I know you said you aren't interested in changing your soap and wax supply method, but if you ever think you might I can give you a list of the check valves and solenoids that are near 100% reliable in my experience. I've remodeled a couple washes with the zero pressure regulators, seemed like a good idea at the time since they were both having severe manifold washout and seal failure issues because of having a tiny open tank for each pump, and eliminating the tank in favor of the zero pressure regulators did solve the other maintenance issues, but like you they both had issues with the regulators failing. If only they'd make the cartridge out of stainless steel...

I’m leaning more towards staying with relays. Yeah, I use to cringe when people were speed dialing the rotary switch and the motor relays would pop on and off! Dayton solid state on-delay, relays took care of that, mounted on the load line going to the motor starter. Mine are older ones that are only adjustable from .25 to 1 second. I’ve got them set to 1 second. But it works good. If I stay with the relay system I will probably replace them with new ones that are adjustable to a higher delay time, but 1 second seems to work okay. My pressure injected soap and wax system has been so consistent and reliable that I just don’t want to change it. Ive been using it for about 20 years now.
I rarely ever wash out a head on the high pressure pump with the pressure fed system, I use to fairly regularly with the suction fed system, especially on the check valve seats. I hated those zero pressure regulators!
Thanks!

 

[cmawash]

we had good luck with idx conversion for foam brush system controller, had a programable unit for air systems, it failed and was not in the mood to replace it and having to reprogram the new unit. converted to idx 10 station unit, it also has lights showing if in use. works like a champ

 

[Don B.]

we had good luck with idx conversion for foam brush system controller, had a programable unit for air systems, it failed and was not in the mood to replace it and having to reprogram the new unit. converted to idx 10 station unit, it also has lights showing if in use. works like a champ

Well, I know they’ve been around a long time so they must be fairly reliable. Haven’t decided which way to go yet. I sure might try them. They would make a much neater and cleaner install. There’s actually not much difference in price between a set of new relays, plus a time delay relay, compared to a multiplex controller.
Thanks!

 

[Greg Pack]

IDX multiplexers have been very reliable for me. Just fuse the output in case you have a motor or other short.

 

[Randy]

I think I used my first IDX MX-8 around 1994. We’ve installed a lot of them since then and haven’t had any fail yet that I know of. We do the same thing on the MX-8 that we do with the vac timers and install a relay and have the MX-8 control the relay so there is very little load on the MX-8. We install the MX-8 in an air conditioner shut off can, gives it a nice clean install look.

 

[MEP001]

The only time I'd use the MX-8 output direct would be to switch a solenoid.

 

[Don B.]

IDX multiplexers have been very reliable for me. Just fuse the output in case you have a motor or other short.

Do you use the multiplex in place of a motor contactor and just wire the output load right to the motor and use it to run the motor?

 

[Don B.]

I think I used my first IDX MX-8 around 1994. We’ve installed a lot of them since then and haven’t had any fail yet that I know of. We do the same thing on the MX-8 that we do with the vac timers and install a relay and have the MX-8 control the relay so there is very little load on the MX-8. We install the MX-8 in an air conditioner shut off can, gives it a nice clean install look.

Yes, I would wire it to energize the motor contactor coil. It certainly sounds like you have had good luck with them!

 

[MEP001]

Do you use the multiplex in place of a motor contactor and just wire the output load right to the motor and use it to run the motor?

You can, the output is pretty robust, but taking the load off a piece of hardware like that is always a good idea. You can get HVAC contactors rated for 30 amps for $15 or a mercury displacement relay for $35 that will last forever.

 

[Don B.]

You can, the output is pretty robust, but taking the load off a piece of hardware like that is always a good idea. You can get HVAC contactors rated for 30 amps for $15 or a mercury displacement relay for $35 that will last forever.

I don’t know if I would want to run the motor straight off of it. Never thought of using a mercury relay to run a motor. Probably would last forever. I use the 30 amp 2 pole contactors.

 

[MEP001]

I use the 35 amp mercury relay on vacs. I've seen a coil fail, but not the contacts.

 

[Don B.]

I use the 35 amp mercury relay on vacs. I've seen a coil fail, but not the contacts.

I forgot they use those on vacuums.

 

[Greg Pack]

Do you use the multiplex in place of a motor contactor and just wire the output load right to the motor and use it to run the motor?

Either way. The coleman pumping units I've had in the past built in the 2000s didn't have a relay. I think the MX-10s have a 20 amp rating, could be wrong. The only time I have lost one was years ago when a motor shorted out and burned up the SCR. I install a cheap inline glass fuse on the units. Haven't lost one since. But I do have one on a contactor at another wash. It's the most relaible product IDX sells.

 

[MEP001]

Kleen-Rite says 25 amp, but they get stuff like that wrong all the time.

Sonny's shows all IDX products as discontinued.

 

[Don B.]

Either way. The coleman pumping units I've had in the past built in the 2000s didn't have a relay. I think the MX-10s have a 20 amp rating, could be wrong. The only time I have lost one was years ago when a motor shorted out and burned up the SCR. I install a cheap inline glass fuse on the units. Haven't lost one since. But I do have one on a contactor at another wash. It's the most relaible product IDX sells.

I had no idea you could run the motor straight off of it! I always figured you just used it to latch the motor relay! Yeah, you would definitely want to put a fuse in-line on the load.
I am seriously thinking about using them instead of relays! I’ll try anything once!

 

[Don B.]

Kleen-Rite says 25 amp, but they get stuff like that wrong all the time.

Sonny's shows all IDX products as discontinued.

As in out of business?

 

[Randy]

As in out of business?

No I think IDX is still in business.

 

[MEP001]

As in out of business?

They were having supply issues after COVID, and a lot of their products were very delayed. It could be a mistake on Sonny's end, but every IDX item except the AT411E vacuum timer shows out of stock on Kleen-Rite's site.