Rotary switch function delay

[I.B. Washincars]

I think you guys are wasting to much time trying to solve a problem that only exists in your mind. I have a couple of 18 year old washes and two others that are 12 years old. I hear the pumps starting and stopping as the dial is spun every day. I don't think I have ever had to replace a pump contactor and just replaced the first motor yesterday, an 18 year old Leeson.

 

[Rudy]

Every time a pump tries to start up, the "demand" part of your electric bill increases. You are billing billed for two things....demand, and usage. An 18 year old wash could have saved hundreds on the electric bill just by installing these cheap devices.

 

[MEP001]

I don't think I have ever had to replace a pump contactor and just replaced the first motor yesterday, an 18 year old Leeson.

What if the motor would have lasted 30 years if you'd had delay timers on them? I guess we'll never know.

I'm not convinced myself that unnecessary starting/stopping of the motor shortens its life significantly, but it sure makes me feel better not hearing it turn on/off 20 times in 3 seconds because someone thinks the switch is a playtoy, or never learned to read and the friggin' picture of the foam brush on the "FOAM BRUSH" position just isn't clear enough.

 

[MEP001]

Every time a pump tries to start up, the "demand" part of your electric bill increases.

Not everyone pays a "demand" rate.

 

[Randy]

In 26 years I?ve replaced 1 motor contactor. Years ago it bothered me to hear the motor contactor cycle when the rotary switch would be spun around, it doesn?t bother me anymore, I?ve got bigger things to worry about.

 

[mjwalsh]

When we put in our touchpads back in 1987 the transitions were & is taken care of with the distribution board.

PLC & durable off the shelf buttons seems to be the ideal way. At this time I do not have that much experience with PLCs yet. Maybe I am naive but it seems like it is "all blue sky" with PLCs when it comes to addressing whatever.

I agree with the demand issue & anything that extends the life of the motors & probably the motor starter relays.

 

[Ric]

While the "delay before make" timer is better than nothing, the best setup is a "delay before make and delay before break" timer.

When a customer starts with high pressure soap, and then switches to high pressure rinse, and then to high pressure wax....the pump never stops. This would not be true if you only had the "delay before make" timer.

But what would happen if the customer switched from a high pressure function to a low pressure function? Wouldn't the hp pump stay running and the low pressure function run also? For instance the hp pump and the spot free delivery pump (or tire cleaner, pre-soak, etc.) would run at the same time briefly. Could that be an issue?

 

[MEP001]

I put a delay on the spot-free and high-pressure, so even if what you suggest might be an issue (which I don't think it would) it won't happen anyway. We use a Cat 390 pump/5HP motor for spot-free, so I wanted it delayed just like the other 5-HP motors. Low-pressure functions shouldn't be bothered by it, especially if you're using Flojet pumps. A Procon shouldn't be run without a bypass regulator anyway, so a brief run with no flow should be a complete non-issue. Older bladder tank systems and Flojets that dead-head against the solenoids wouldn't be bothered at all. Even the spot-free shouldn't be bothered with a 1- or 2-second run with no flow if it's all set up properly.

 

[Rudy]

Yes, you are correct. The HP function runs for 2 seconds extra. You have check valves already that protect from "back feeding" the LP functions.

Regarding "not all people get charged for demand", I just recently read somewhere that in an effort to increase profitability, many utilities are not only charging for demand, but also installing more sophisticated meters. These meters use an advanced method to determine "demand" which is under reported by the cheaper meters.

Bottom line....demand is going to cost you more. If you can stagger motors coming on line....you'll save.

 

[Twodose]

Dilling-Harris has them. Little black box about 1.5" square, I think 2 sec delay, Very simple to hook up. You can't change the delay time. I have them in all my bays.

 

[MEP001]

It may just be me, but two seconds seems too long. One second has been plenty to keep the pumps from excessive starting/stopping, and the customers don't get confused when the function doesn't come on right away.