Time delay relay suggestions?

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I'm looking at changing a 1 HP pool motor to a two speed motor to save energy. A motor running at half speed can move the same amount of water using a lot less electricity. The problem is the system has a solar heater and from researching online it appears that there is a good chance that the pump will need to start on high speed to get it flowing, then it can switch to low speed to keep it going.
So, the question is, any suggestions for an appropriate 240V time delay relay, ie a relay where there is either a fixed or adjustable time delay of about a minute? I've looked online and there appear to be a lot of them, but they are either for rack mounting or else they have some kind of pins that then plug into a socket. I guess I could find a socket, figure out how to mount it, etc, but I was wondering if anyone knows of a relay better suited to easily mounting/wiring into a typical electrical box? Will need a box for a low/high switch and looking for something that could easily go in there. I may not need it if it will get going on low, but figured it's kind of slow here lately and might as well be prepared.
TIA for any help.
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On Fri, 18 Apr 2014 05:41:36 -0700 (PDT), trader_4

A lot of these that can use a socket, also have a threaded base that accepts a screw so you can mount them just about anywhere and the pins for the socket will take a regular spade connector.
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On 4/18/2014 12:34 PM, trader_4 wrote: ...

What kind of a budget do you have here?
Newark and/or Mouser will be able to supply what you're looking for, but it's likely $100 min for the rating.
The cheapest I found in a very quick perusal at <$50 is rated 1/2 hp 240V--
<http://www.newark.com/pdfs/datasheets/SE_Relays/TDRSRXB-240A.pdf
--



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On Friday, April 18, 2014 2:36:39 PM UTC-4, dpb wrote:

I was hoping for under $35, but if it turns out I need it, then even if it costs $100 it will still be worth it in money savings, just a longer payback....

That's the problem I was having on Ebay. Lots of cheap brand new ones for even $7, but they aren't rated for 1HP. I still think I could probably find something there, but gave up looking because there isn't anyway to quickly zero in on it, ie: 240V coil 240V 1HP contacts SPDT or better Delay ON ~1min
To find it you have to look through a lot of them and there are 1000s there. If it turns out I really need it, I can keep looking.
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On 04/18/2014 08:41 AM, trader_4 wrote:

Single or two phase motor?
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I am sure it is a single phase motor if he is going to use it on the US grid. I bet you meant 120v or 240v. ;-)
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On 04/18/2014 04:04 PM, snipped-for-privacy@aol.com wrote:

Trader_4 thinks 240v center tap is 2-phase service.
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On Friday, April 18, 2014 5:08:53 PM UTC-4, Bubba wrote:

Since you want to bring that crap up all over again, let me say that I never called it two phase service. Just like I wouldn't call Kleenex soft white paper made from trees. But that's what Kleenex is and just as surely there are two phases present in a 240/120V service. That it's not commonly refered to that way from a power industry perspective, doesn't change what is physically there.
IEEE power system engineers agree:
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber4520128
"Distribution engineers have treated the standard "singlephase" distributio n transformer connection as single phase because from the primary side of t he transformer these connections are single phase and in the case of standa rd rural distribution single phase line to ground. However, with the advent of detailed circuit modeling we are beginning to see distribution modeling and analysis being accomplished past the transformer to the secondary. Whi ch now brings into focus the reality that standard 120/240 secondary system s are not single phase line to ground systems, instead they are three wire systems with two phases and one ground wires. Further, the standard 120/240 secondary is different from the two phase primary system in that the secon dary phases are separated by 180 degrees instead of three phases separated by 120 degrees. "
So do electrical eqpt manufacturers:
http://www.samlexamerica.com/support/documents/WhitePaper-120240VACSingleSp litPhaseandMultiWireBranchCircuits.pdf
http://www.behlman.com/applications/AC%20basics.pdf
And if you disagree with them, perhaps you can answer the questions I pose in this simple exercise. Simple questions that no one on the other side of this will address, because they can't. Let's start with a 3 phase system. I have 3 phases and a neutral coming into a building. Everyone agrees there are 3 phases separated by 120 deg. Now let;s get rid of one. How many phases are there now? Two obviously. Now let's make the phase difference 160 deg between them, instead of 120. How many phases now? Still two? Now let's change the phase angle so that they are 180 deg apart. How many phases now? If it's not two, explain the magic that just happened. And if it is two, then adjust the voltages and you have a service that is identical to 240/120V split phase. The electrons flow exactly the same way and electrically it is indistinguishable from 240/120V split-phase.
QED
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On Fri, 18 Apr 2014 05:41:36 -0700 (PDT), trader_4

I think I would just try it first before I changed anything. My 2 speed spa pump gets the water up to the solars on the 1/10th HP speed. I was thinking just like you but I figured out it was working without it. It does take a few minutes to actually get the flow going but once it does, it works fine. The pump is not cavitating or running dry, it is just taking that long for the water at that head to get up there.
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On Friday, April 18, 2014 4:14:31 PM UTC-4, snipped-for-privacy@aol.com wrote:

Yes, I plan to try it without the relay first and figure it may work. I just figured I'd be further ahead if it turns out I do need it. And it's been kind of slow here, except for the political threads...
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On Fri, 18 Apr 2014 13:27:24 -0700 (PDT), trader_4

You could split the problem up and buy the appropriate double throw relay and use a 555 timer to kick it off for a minute or so
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On Friday, April 18, 2014 4:51:15 PM UTC-4, snipped-for-privacy@aol.com wrote:

Great minds must think alike. I was just back at Ebay looking and came to a similar solution. They have cheap $5 240V time delay relays that will switch a few amps. And I found a beefy regular 240V power relay for $17:
http://www.ebay.com/itm/MAGNECRAFT-725BXXBC3ML-240A-Relay-Power-6-Pin-DPST-NO-25A-240VAC-/321338876102?pt=LH_DefaultDomain_0&hash=item4ad14a20c6
So, worse case I can use one relay to drive the second relay. While not ideal, it may be hard to beat on price, < $25 total.
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On Friday, April 18, 2014 5:04:57 PM UTC-4, trader_4 wrote:

Doh! After posting the above, I realized it's DPST. I need DT, but the approach is still vaild, just need to find a SPDT or DPDT power relay.
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On 4/18/2014 4:08 PM, Bubba wrote:

Oh, is he the one? Went 'round and over that just a few weeks ago...
--


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On 4/18/2014 3:34 PM, trader_4 wrote: ...

If you're not wedded to the idea of the integrated delay coil, options for just the relay are much wider...
You can sort/search at Newark or Mouser
Here's
Coil >0VAC Load >#0VAC, > A Contacts - DPDT
From $15 up depending on various other things...
Well, I was too lazy to go get the short URL but use the search engine at
<http://www.newark.com/power-general-purpose I got 50 or so I think...
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I would first just try it on low speed and see how it works.
The cost and complexity of a time delay relay will probably not pay back.
Mark
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On 4/18/2014 7:20 PM, trader_4 wrote: ...

Which is _exactly_ what I tried to tell you some time back that you refused to heed. It's two separate uses of the word "phase".
--



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On Friday, April 18, 2014 8:23:34 PM UTC-4, dpb wrote:

That I refused to heed? Good grief. Now the story changes. The issue was never about two separate uses of the word phase. Go back to where it all started. Someone claimed that you can't say that there are two hot legs that are 180 deg out of phase with each other in a 240/120V split-phase service. That is how it started. I posted my position, backed up by the IEEE and the other sources, which agree that there are two phases present. And I clearly said right from the beginning that I would not call a 240/120V split phase service "two phase service", because that isn't how it's commonly referred to. It's not referred to as two phase, because from the power company perspective, what comes into the house over those 3 wires originates from one phase on their generating system. But that doesn't change what is electrically there and that you can see on a scope.
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On Saturday, April 19, 2014 8:44:57 AM UTC-4, trader_4 wrote:

Darn it, we wouldn't have this problem if we listened to Edison and went with DC.
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We just call them two ungrounded conductors, single phase.
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