Hi All! I hope i am posting in the appropriate area/forum.

I have a project that i am trying to complete and am having a really hard time figureing it out. I had someone helping me design this but he fell off the face of the earth

I am putting together an electric pressure washer and need todo the following: when the sensor stops sensing the flow of water it triggers the relay but delay the motor shutting off for 10-15 seconds.

the key though is to have a 10-15 second off timer that way it doesnt stress the motor everytime if squeeze the trigger, especially walking around the vehicles. I thought i had this but realized the relay i found isnt robust enough to handle the motor.

These are the parts I was told to purchase: (Its Safe) https://www.dropbox.com/sh/wnltxzm3s2r90ob/AABvxZvtMgnW1gMqqkozEOlua

The flow sensor attaches to the output of the pressure washer pump.

And this is the motor I purchased http://www.baldor.com/products/deta...inglePhase&winding=36WGW903&rating=40CMB-CONT

I simply need a 10-15 second delay and someway to trigger the contactor and overload circuit (together make the "motor starter?")

At this point i think i need a transformer to drop down the voltage for a relay that attaches to the flow sensor ? Is the overload circuit my relay from the timer to turn the motor on?

I also assume for an ON/OFF switch I would just "break" the sensor wire?

I'm becoming frustrated because i just cant "get this" I feel like this is overly simple and i should be able to figure this out , but there is just not really any information out there on how todo this.

Im trying to build a box that looks like this:

It has an on/off switch-status light-reset switch



Thank you i really appreciate any help or guidance with this, i would also be willing to pay for someones time to come up with a diagram and remaining parts list.

 

Are you sure the flow sensor you have will handle the output pressure of the pressure washer? Or do you plan on putting it on the inlet side of the high pressure pump?

For the timer, you could use one of these.......
http://www.ebay.com/itm/ATC-SERIES-...252?pt=LH_DefaultDomain_0&hash=item27e71085bc

 

As long as you have these parts. 240V coil.
Might as well get a 240V timer as well.
http://www.ebay.com/itm/1A-220VAC-P...546?pt=LH_DefaultDomain_0&hash=item2a36923b5a


Wiring is pretty straight forward.

Power goes to L1 and L2 (top)
Overload assembly connects to T1 and T2 (bottom)
Motor connects to bottom of O.L.

Control wiring: connect L2 to coil terminal #2.

L1 thru (fuse)-(switch)-(timer N.O. contacts)-(O.L contacts)-(coil terminal #1)

Timer powered from L2 and switched L1.
Timer triggered from flow switch.

You may find a timer with "no voltage" trigger if you don't want mains power on flow switch.

 

Are you sure the flow sensor you have will handle the output pressure of the pressure washer? Or do you plan on putting it on the inlet side of the high pressure pump?

For the timer, you could use one of these.......
http://www.ebay.com/itm/ATC-SERIES-...252?pt=LH_DefaultDomain_0&hash=item27e71085bc

Yup! it is designed to handle up to 4800PSI. The pump ill be using is only 2000psi so i have a safety margin built in!

As long as you have these parts. 240V coil.
Might as well get a 240V timer as well.
http://www.ebay.com/itm/1A-220VAC-P...546?pt=LH_DefaultDomain_0&hash=item2a36923b5a


Wiring is pretty straight forward.

Power goes to L1 and L2 (top)
Overload assembly connects to T1 and T2 (bottom)
Motor connects to bottom of O.L.

Control wiring: connect L2 to coil terminal #2.

L1 thru (fuse)-(switch)-(timer N.O. contacts)-(O.L contacts)-(coil terminal #1)

Timer powered from L2 and switched L1.
Timer triggered from flow switch.

You may find a timer with "no voltage" trigger if you don't want mains power on flow switch.

Thank you very much for your post, i really appreciate it.

So do i jump power from the top of the contactor at l2 to the number 2 terminal on the timer?

L1 jumped to a fuse then on/off switch then to the timer then to contacts? then back up to3?

sorry i am very far out of my element here. When i took on this project i thought it would be easier then just buying one premade (its still cheaper) but i have hours into research and now I want to finish it since ive got so much time invested into it.

as you said its straightforward, its just a matter of wiring up something like this, and of course i want to make it safe.

I would prefer not to have voltage at the switch if possible even though it seems the switch can handle it? after about an hour of searching google i cant find anything so maybe i need to have it there.

thanks! i really appreciate your help and time with this

 

I'll look for a 220v timer with low voltage trigger.

Else use a transformer or power supply.

Have you purchased the equipment?

I had a similar project the other day. 480v motor where I didn't want the cord connected controls HV.

I found a used combination starter for $200.
Of course that was a size 0. You need a size 2.

A combination starter has everything you need. Prewired and approved.

Enclosure
Main disconnect
Main fuses
Starter
Overload assembly-reset button thru cover
Transformer with appropriate fusing
Hand/auto button

All you do is add the timer to the "auto" leads.

 

Wait if i read your post right (and ive read it many times) i need to get a coil too?

 

Sorry our internet went out with the storm coming though so just saw that you posted more.

The only thing ive purchased is the contactor and OL. and of course the sensor and motor. Im not in too deep financially in the contactor and OL. if there is already a premade setup that is tested and approved, which would make it safer.

I know its alot to ask but would you have one that you would recomend and a timer! i think this is the better route to go, dont you think?

Thanks again!!! i REALLY appreciate it

EDIT: just did a quick search, saw that there are TONS of them out there ranging from a few hundred to a few thousand....I cant imagine my setup would warrant for one being in the thousands, Would you? considering the production model of the presusre washer pictured in the first post is small!

 

I'll keep looking.

How do you feel about used equipment?
I should have mentioned that. New price may be out of your budget.
Nema rated starters are near bullet proof. I buy used ones all the time. Contacts almost always are "as new".

I'll also look for a generic schematic. I'm not up to drawing one right now.

I think max posted a link to generic motor starter circuits a while back!

 

Here ya go!
I haven't checked it yet.
Timer and flow switch replaces fan switch.
Ignore L3 and T3

 

I'll keep looking.

How do you feel about used equipment?
I should have mentioned that. New price may be out of your budget.
Nema rated starters are near bullet proof. I buy used ones all the time. Contacts almost always are "as new".

I'll also look for a generic schematic. I'm not up to drawing one right now.

I think max posted a link to generic motor starter circuits a while back!

Im totally cool with used equipment! especially since this will be mounted in my garage and only used 1 to 2 times a week!

 

Do you have proper wiring for the 5hp?

50 amp circuit and #8cu wiring/outlet/cord.

Welder or range outlet should work

 

Do you have proper wiring for the 5hp?

50 amp circuit and #8cu wiring/outlet/cord.

Welder or range outlet should work

Not yet but can easily be obtained and installed. The motor looks to only draw 23amps, I was told by the guy before to get a 30amp GFCI breaker even though the production version only calls for 20amp. Should I replace it and get a 50amp GFCI breaker? here is the spec sheet for the one im modeling mine after http://www.bepressure.com/uploads/Products/product_20/X-2050FW1COM.pdf

I havent bought much because i was waiting on the control box to be completed and the specs of what is needed

 

Should be fine with 30 amp circuit and #10 cu. then.
Must be lightly loaded 5hp.

I was going by nec 5hp rating.

 

This is a good start til I find something better.

http://www.ebay.com/itm/ALLEN-BRADL...390?pt=LH_DefaultDomain_0&hash=item4d205c0d2e

 

Found a box with 24v fused transformers, two timers, and room for starter.

All it would need is selector switch, 24v contactor, and your overloads.

 

Only question I have is about the flow switch. Is it a flow or pressure switch?

When the flow stops, motor will stop after delay.

How will motor restart if there is no flow? Is there enough residual pressure that there will be flow when squeezing trigger?

With a pressure switch it would turn off after "over pressure" from closed trigger.

Then restart after trigger relieved "over pressure".

 

Only question I have is about the flow switch. Is it a flow or pressure switch?

When the flow stops, motor will stop after delay.

How will motor restart if there is no flow? Is there enough residual pressure that there will be flow when squeezing trigger?

With a pressure switch it would turn off after "over pressure" from closed trigger.

Then restart after trigger relieved "over pressure".

Sorry for the delay...we've been battling internet outages all day.

Is that box in the picture stuff from your surplus? or ebay?

there is enough "wall pressure" to activate the flow switch. It is actually a flow switch, magnetic if i recall the specs correctly. it is identical to the one BE pressure uses.

Thanks Again!!!!!

 

It could be mine.
Picked it up from my brothers surplus store.

From time to time I'll load up some goodies and put them on Ebay for him.

If this is something you want, I'll PM you.
If not, I think it's generic enough that I can use it or list it.
I mean, who wouldn't want a 5hp starter/24V transformer/timer/hand-auto/package?

It comes with the extra universal timer.

If you look at the lower left under the contactor. There is a loop of gray wire. That gets cut and connected to the overload assembly.

In the middle are two orange wires from a terminal strip. Touching them together in auto mode runs motor until they are opened and timer runs out.

Other than that it's good to go. Well under budget.

No points for neatness. Remember, I'm making do with what I found.

 

I'm taking your word for switch operation. link?

If it is a switch that can switch 24vac on with flow and off with no flow, we are good to go.

2 wires?
Normally open? (closes with flow)

 

I have it reversed now, so no flow closes switch, and "delay on" times out to stop motor.
Should read "no" flow closes to stop motor.