Solid state relay questions

[et...@whidbey.com]

My water comes from a well. When the well was drilled I had only
built my shop and so the well is now powered by my shop. The pressure
tank and switch is also at the shop.
Now that the house is built I need to power the well from the
house. This is fine but I am not gonna move the pressure tank and the
pump switch must be at the tank for proper operation.
The problem I must address is how to use the switch at the tank
while using power from the house. I cannot run power from the house to
the tank and then to the well pump because the voltage drop would be
too great due to the much longer run of wire.
My plan is to instead use the existing wires coming from the shop
and going to the well to just carry switching power, not pump power. I
want to use a couple solid state relays, one for each leg of the 240
power, to switch the power to the well. There is plenty of room to
mount two solid state relays inside the well junction box. And I found
AC controlled solid state relays that use 80 to 280 volts AC for
control and will switch up to 480 volts AC at 25 amps. My well pump is
a 2 HP pump that draws less than 10 amps. It is a capacitor start
type pump so it draws less current at start up than a non-capacitor
type pump.
So, my questions: Are solid state relays suitable for this type of
work? Are they typically able to handle surge current loads from motor
starting? Here is a link to the relay in question:
https://www.mpja.com/download/33984-86RLData.pdf
Thanks,
Eric

[Phil Allison]

et...@whidbey.com wrote:

========================

> So, my questions: Are solid state relays suitable for this type of
> work? Are they typically able to handle surge current loads from motor
> starting? Here is a link to the relay in question:
> https://www.mpja.com/download/33984-86RLData.pdf
>

** That is a no brand, triac based SSR.

Nice and cheap - right ?

Triacs cannot take over current surges that last more than a cycle or two.

Why use 2 in series ? I can only see that causing problems.




.... Phil

[peterw...@gmail.com]

This is water for your house. That means that it is a critical function.

Cut the crap about what you 'can' or 'cannot' do. It is only money, and you owe it to yourself and any (possibly unfortunate) family as may also need reliable water on rare occasion. Start over, do it right and sleep well. Do anything else, and be prepared for the worst possible scenario.

Keep in mind that this forum exists so that the uninformed may provide the least appropriate, most complicated, least reliable solutions for established problems with established (and reliable) solutions such that the requester of such information may be relieved of taking responsibility to do the right thing in the first place.

Peter WIeck
Melrose Park, PA

[peterw...@gmail.com]

Line drop. Bullshit. Use #6 copper UF cable, and the line-drop for a 400-foot run is 2.53 volts at 8 amps (1920 watts).

Repeat: cut the BS and do it right.

Peter WIeck
Melrose Park, PA

https://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=1.296&voltage=240&phase=ac&noofconductor=1&distance=400&distanceunit=feet&amperes=8&x=68&y=10

[Paul Drahn]

MY well is powered from the shop line as well as your well. The
shop/garage is on a separate 100 amp line from the service point. The
house is a 200 amp line from the same service point.

Why do you need to change the source of service to the pump?

Paul

[et...@whidbey.com]

On Mon, 10 Aug 2020 08:09:59 -0700, Paul Drahn <pdr...@jodeco.com>
wrote:

The house has a generator for when the power goes out. The shop does
not. This is why the change in power source.
Eric

[et...@whidbey.com]

Pete-I already have the wire in the ground. It is sized correctly
for the length of the runs. I am not going to dig more ditches. And
what is wrong with using the existing switch to control a relay
instead of the pump directly? Would it be dangerous? Not meet code?
Would a different relay be better?
Eric

[peterw...@gmail.com]

The below was in the can when your next message came through. There are any number of bad reasons to do it the way you suggest. Relays have their issues, and they tend to fail at the worst possible time under the worst possible conditions. I understand that you are not in downtown Seattle, nor even close to it, so surety and/or redundancy is a big concern. So, if you must use a relay-switch, use one rated for short-cycling and for heavy currents. Also known as a Definite-Purpose Contactor-Switch.

https://assets.alliedelec.com/c_scale,w_600,f_auto,q_auto,d_no_image.png/70060527_front.jpg

https://images.homedepot-static.com/productImages/c772b9e9-9e09-4724-aaf6-9ae10e28a64d/svn/noark-motor-controls-ex9ck30b20g7-64_1000.jpg

Of many, many options. This will let you control a 240 VAC line from a 120 VAC line. The activator coil options are many, from 12V to 240V. One bit of advice - DO NOT cheap out on these parts.

Peter Wieck
Melrose Park, PA


__________________________________________________________________________________________________________________
And you do understand what happens to SS (any, actually) relays when they get stuttered power? Such as when a transfer switch kicks in and out? Nothing solid-state likes to be short-cycled unless designed specifically for that. And even mechanical relays wear heavily if short-cycled.

Repeat: Bite the proverbial bullet, run a new heavy-gauge line to the well system, and be done with it. The first time you do not have to go schlepping out to the shop in a howling windstorm you will bless that decision.

Peter Wieck
Melrose Park, PA

[et...@whidbey.com]

I'm not gonna cheap out on components. And I'm not gonna run 400 feet
minimum of #6 wire. Nor am I gonna dig more ditches in my finished
yard. I am gonna have an extra relay in the control box, just like I
have an extra pressure switch at the pressure tank. Could you please
explain why a relay controlled by a remote switch is a bad idea? BTW,
thanks for the links. I have decided to not use solid state devices
but instead will use a sealed realy.
Eric

[peterw...@gmail.com]

> Could you please
> explain why a relay controlled by a remote switch is a bad idea? BTW,
> thanks for the links.

a) Because a relay is _NOT_ typically rated for motor-start loads.
b) Because a relay is not designed for the purpose you suggest.
c) Because a relay does not accept abuse very well.

Whereas:
a) A definite-purpose contactor _IS_ rated for whatever motor load you choose (it's only money).
b) A definite-purpose contactor _IS_ designed to turn motors on and off, as needed and as often as needed.
c) A definite-purpose contactor _MAY_ be designed against any number of coil voltages.
d) A definite-purpose contactor _IS_ quite reliable if installed correctly.
e) A definite-purpose contactor will take a great deal of abuse. In point of fact, they were developed for exactly the sort of scenario you suggest.

Again - this venue may often get used as a means to avoid the safe-and-correct solution in preference for the Kluge solution - but that does not make that solution correct, nor safe, nor reasonable.

Keep in mind that any problem with electricity, motors, and controls for same has, at some point in the last 130 years or so, been addressed and managed. Most, quite elegantly. Reinventing a simple wheel only for the sake of that reinvention is always futile, often silly, and all too often, dangerous.

[et...@whidbey.com]

I guess I should have said contactor, which is just a special type of
relay.
Eric

[peterw...@gmail.com]

Much as a Ducati or a Triumph or a BMW is a special sort of Scooter.

[Adrian Caspersz]

On 10/08/2020 21:34, pf...@aol.com wrote:
> Much as a Ducati or a Triumph or a BMW is a special sort of Scooter.
>

https://en.wikipedia.org/wiki/Contactor

--
Adrian C

[Michael Terrell]

On Sunday, August 9, 2020 at 9:26:55 PM UTC-4, pf...@aol.com wrote:
> Line drop. Bullshit. Use #6 copper UF cable, and the line-drop for a 400-foot run is 2.53 volts at 8 amps (1920 watts).
>
> Repeat: cut the BS and do it right.

Or use a boost transformer to compensate for the drop, but only to power the pump.

[Michael Terrell]

On Saturday, August 8, 2020 at 3:40:57 PM UTC-4, et...@whidbey.com wrote:
> My water comes from a well. When the well was drilled I had only
> built my shop and so the well is now powered by my shop. The pressure
> tank and switch is also at the shop.
> Now that the house is built I need to power the well from the
> house. This is fine but I am not gonna move the pressure tank and the
> pump switch must be at the tank for proper operation.
> The problem I must address is how to use the switch at the tank
> while using power from the house. I cannot run power from the house to
> the tank and then to the well pump because the voltage drop would be
> too great due to the much longer run of wire.
> My plan is to instead use the existing wires coming from the shop
> and going to the well to just carry switching power, not pump power. I
> want to use a couple solid state relays, one for each leg of the 240
> power, to switch the power to the well. There is plenty of room to
> mount two solid state relays inside the well junction box. And I found
> AC controlled solid state relays that use 80 to 280 volts AC for
> control and will switch up to 480 volts AC at 25 amps. My well pump is
> a 2 HP pump that draws less than 10 amps. It is a capacitor start
> type pump so it draws less current at start up than a non-capacitor
> type pump.

Why isn't the switch at the pump? How are you going to get power from the house to the pump, without new a new power line?

[peterw...@gmail.com]

> Why isn't the switch at the pump? How are you going to get power from the house to the pump, without new a new power line?

After all this confusion - I expect that the OP means to "control" the pump from the house. If I can interpret the issue (risky, always).
a) The house has a back-up generator.
b) The line to the pump is from the house, but the power to the tank is from the shop, not backed up.
c) The pressure switch is at the tank.

I interpret this to mean that a 120V pressure-switch is controlling a 240V pump, powered by two different sources. Which is flat-out nuts.

I am interpreting (again, risky) that the OP wants the controls at the pump.

So, the 120V source at the shop will control a 240V (hopefully) contactor at the pump.

All the while forgetting that if there is a power-failure, that 120V source will be dead - so, no water.

Clue 1: The tank does not care where it is in the system.
Clue 2: The tank will be perfectly happy staying where it is, with all controls, pressure-switch, contactor and so forth at the pump - in suitable enclosures, of course.

[et...@whidbey.com]

The tank and pressure switch are at the shop and have been so for
over 20 years. The pressure switch has two contacts. The 240 volt
power from the shop, where the tank and pressure switch are, is
switched by the pressure switch. The pressure switch has a completely
mechanical action. The pressure switch switches both legs of the 240
volt power.
When the house was built and I was digging ditches I put conduit in
the ground from the house to the well so that I could eventually power

the well from the house.

Now that I have the generator panel and transfer switch installed
and bought off at the house I want to power the well from the house so
that the generator will be able to power the well when the power goes
out.
I pulled wire from the house to the well to supply power, so now
power from the house is at the well head.
The pressure switch must be located at the pressure tank for proper
operation.
I am not going to move the pressure tank.
So all I want to do is to use the existing pressure switch to
switch the power to a contactor coil. The power for the contactor
coil that the pressure switch will be switching will be coming from
the house. The contactor will be switching the power coming from the
house. There will no longer be any power coming from the shop. Nowhere
did I say any switch was 120 volts. What is wrong with doing this?
Eric

[Michael Terrell]

He could have easily buried a new power line to the tank when he installed the plumbing, as well. I am rebuilding my pumphouse and rewiring it. It will have a couple AC Ammeters and a line voltage meter to monitor the pump's health, along with a one minute lockout between pump cycles. Te old pump failed, but All I could check was the voltage, since there were no current transformers in place. One till monitor the current to the run winding,, the other will show total current. The voltmeter's use is obvious. The timer is to prevent overheating of the start capacitor, if the potential relay fails, again. I have a new submersible pump, and two pump control boxes, so it an be swapped out without waiting for spare parts. The old pump lasted 22 years. That is a long life, with Florida's very hard water.

[Michael Terrell]

On Thursday, August 13, 2020 at 12:00:47 PM UTC-4, et...@whidbey.com wrote:

I have never seen one installed that way. Why not just put the pressure switch at the house, if you insist on not locating it at the pump? That would eliminate all of the jury rigged crap that wouldn't pass an inspection.

[Ron D.]

Comments:

1. use a definite purpose contactor.

2. the pressure switch might have a minimum load, so if those contacts are used to switch a relay coil, they may fail.

[peterw...@gmail.com]

http://store.flw.com/content/100608/43609/ashcroft-b-series-pressure-switch.pdf

I also think that putting the pressure switch next to the well-head is a good idea. The tank really does not care where it is in the system.

[et...@whidbey.com]

Water well pressure switches should always be placed as close to the
pressure tank as possible. Within 1 foot is best. Nearly 300 feet away
at the well head would be a bad idea.
Eric

[peterw...@gmail.com]

> Water well pressure switches should always be placed as close to the
> pressure tank as possible. Within 1 foot is best. Nearly 300 feet away
> at the well head would be a bad idea.

That posits a conventional pressure switch. If I understand correctly, your well is some distance from your house, and the tank is some distance from your well - by your description, some 300 feet. You also state that the pressure switch is 100% mechanical in action, and capable of switching the 240 Volts to the pump. You intend to re-purpose that switch to activate a contactor switching pump power from the house - because there is an emergency generator at the house. So, being a bear of little brain, I am trying to understand how you intend to do this:

a) Take power from the line at the pump and send it to the Pressure Switch, then back to the contactor to activate it. Makes sense if you have a ground and a neutral in the run between the pressure switch and the pump and the same to the well-head from the house - 240V 4-wire (hot/hot/neutral/ground) allowing you to use 120V as the coil voltage. This makes all voltage to the pump and its controls originate at the house. If carefully managed, and all the conductors are the correct gauge, this will even meet codes. However, you need to verify that the pressure switch is properly rated (most are).

b) Use the existing power from the shed to activate the coil - problematic as you have two different power-sources in the same panel - able to be managed, but code compliance, again, is problematic. And, if the power goes out, so does the well as there is no power to run the coil.

I sent you to an industrial pressure switch sophisticated enough to account for the lag due to the distance from the tank. As the tank is (apparently) doing its job as far as house-pressure is concerned, it can continue to serve with a distant pressure switch if that switch can be programmed to include the lag. This keeps all your controls in one place, served by one source, with fewer failure opportunities. All good when a critical function is being covered.

We have a similar set-up here for the diesel fire-pumps and generators scattered across 1,200,000 square feet of building covering a city-block. There is a Veeder-Root tank monitor system some 80 feet away from the three x 1,000 gallon underground tanks under the sidewalk outside. This device monitors tank levels, fuel temperature, moisture content and so forth. There are three (3) local pumps on a lead-lag system that feed the day-tanks located at each fire pump and/or generator (total of seven (7)). These are activated as-needed (1/2/3, then 2/3/1, then 3/1/2) as needed - any two can keep up with all seven locations if needed. But, the float-switches in the day-tanks are as much as one flat block and 23 floors away from the USTs and pumps. And, all of these things "talk" to the Veeder-Root, which prints out a status once-per-day, and also a report every time a fill-pump is activated. Point being that the controls are nowhere near the tanks.

[et...@whidbey.com]

The pressure switch at the tank is the typical snap action type
found on every well and air compressor I have seen.
Even though I have 4 wires coming from the shop and going to the
well I will only be using two of them.
I have found several 240 volt coil motor start contactors that are
suitable for switching power to the well.
The power from the house will power both the contactor coil and and
the well pump. The ground and neutral from the shop will not be used
because code says the only ground and neutral for the pump house must
come from a single source. So the generator sub panel is connected to
the main panel ground and no other. The box at the well head will
still have a floating ground and floating neutral, just like the gen.
sub panel, but instead of getting the neutral and ground from the shop
will now get them from the house.
Is there any reason that a 120 volt coil contactor should be used
instead of a 240 volt coil? Since I did run 4 wires from the house as
I did from the shop I could use a 120 volt coil by using the neutral,
but I don't see the point.
There is no reason to relocate the pressure switch as near as I can
tell. The current pressure switch is inexpensive, reliable, and
available 7 days a week even here on the island. Besides, I already
have an extra new one sitting on the shelf. And I already have wires
in the ground going to the switch, so why not use them? They will just
be switching less current. And from what I can tell, the snap action
type of action used in these switches is so the contacts always make
good contact because they slam together. They even slam right through
spiders and beetles. I dunno why the bugs like to hang out on the
switch contacts. Mebbe it's done on a dare.
Thanks,
Eric

[bruce bowser]

I bet doing work after breakfast or lunch with chicken grease, etc.. still on your hands means that more than just beetles and spiders will stay around.

[John Robertson]

On 2020/08/14 3:58 p.m., et...@whidbey.com wrote:
> On Fri, 14 Aug 2020 10:56:02 -0700 (PDT), "pf...@aol.com"
> <peterw...@gmail.com> wrote:
>
>>
>>> Water well pressure switches should always be placed as close to the
>>> pressure tank as possible. Within 1 foot is best. Nearly 300 feet away

>>> at the well head would be a bad idea....

> Besides, I already
> have an extra new one sitting on the shelf. And I already have wires
> in the ground going to the switch, so why not use them? They will just
> be switching less current. And from what I can tell, the snap action
> type of action used in these switches is so the contacts always make
> good contact because they slam together. They even slam right through
> spiders and beetles. I dunno why the bugs like to hang out on the
> switch contacts. Mebbe it's done on a dare.
> Thanks,
> Eric
>

Why are the electrical contacts not in a watertight box? This is a damp
environment, right? The controller(s) should be sealed up to prevent the
risk of moisture, bugs, etc...

As Peter keeps saying, spend the money, get a proper sealed system that
can handle the load, and the environment - or your next water outage
might be in the middle of a house/wood stove/cooking fire during a
blinding snowstorm...

John :-#(#

[et...@whidbey.com]

On Tue, 29 Dec 2020 14:23:12 -0800, John Robertson <sp...@flippers.com>
wrote:

Nobody has their well pump control in a water tight box. They all
breathe. And every pressure switch on every well pressure tank
breathes. My well control is in a box made for outdoor use too, and
yet it still breathes. Though bugs cannot get in the atmosphere
certainly does. Rain could pour over my pressure switch and well
control box all day and nothing would get wet inside, but humidity
will. Nevertheless this does not happen. In any case I bought an
appropriate contactor and mounted it in the well control box.
Everything is fine. The contactor is switched by the pressure tank
switch. The whole setup meets code.
Eric

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[bruce bowser]

That's a free air connection. Its easier to get in to make repairs/additions, just like with an overhead wire connection. Wires in underground conduit might be tough to get to and repair, like after lighting strikes.