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ikram shehzad
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Latching Relay

07/25/2011 1:57 PM

Dear all.

can anyone explain that what is latching relay and how it work,s.

can we use latching relay for 2 pump,s which working perallel to eachother, when one pump is running then other is stop, after sometime that relay cut off that pump and switch on other pump. Is it work loke that?

Please guide me.

Thank,s and Regard,s.

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KJK/USA
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#1

Re: Latching relay

07/25/2011 2:03 PM

If you are trying to alternate the pumps try a "Pump Alternator Panel".

It is a little more involved than a latching relay.

Try this link

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ikram shehzad
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#3
In reply to #1

Re: Latching relay

07/25/2011 2:38 PM

o.k sir thank,s.

but sir, can u tell me the function of latching relay that how it work,s.

Thank,s.

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SimpleMind
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#2

Re: Latching relay

07/25/2011 2:36 PM

Please don't post the same question more than once. Anyway latching relay is a relay type that does not require continuous power on a coil to keep it's contact/no-contact pattern in any of it's stable positions, unlike normal relays that always return in one state. This is accomplished by permanent magnets or spring mechanisms. Just a relatively short duration coil current is used to change between conduction states. Control can be by a single coil, two independent coils, reversing coil polarity etc. S.M.

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rakesh_semwal
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#4

Re: Latching relay

07/25/2011 2:42 PM

A simple DPDT relay with timer will work for your dual pump purpose.
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pnaban
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#5
In reply to #4

Re: Latching relay

07/25/2011 11:42 PM

Can you give details of operation of DPDT relay and circuit?. Can we operate triplex(03 pumps in parallel) pumps similarly?. What is the relay and circuit used?.

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#6
In reply to #5

Re: Latching relay

07/26/2011 1:59 AM

I would consider one of these, or something similar.

It can be used to sequence a small number of pumps or other motors in rotation, with a range of suitable times for changeover.

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pnaban
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#7
In reply to #6

Re: Latching relay

07/26/2011 3:21 AM

Thanks. But there is no description of functions of the relay.

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PWSlack
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#8
In reply to #7

Re: Latching relay

07/26/2011 8:26 AM

A latching relay, once the operating power is removed, stays put in the last position to which it has been driven.

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pnaban
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#10
In reply to #8

Re: Latching relay

07/26/2011 12:00 PM

I need answers from post nos 4 and 6.

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ozzb
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#9

Re: Latching Relay

07/26/2011 9:08 AM

The latching relay electro-mechanically controls the function of two switches. On a signal to the coil the device relieves the pressure on the activation arm of one micro-switch and depresses the activation arm on another and holds it. It then waits for the next signal to switch back to the other micro-switch and holds it.

You will need to provide the external signal. A timer could be used. The contacts on the micro-switches are usually rated at no more then 10 amps. May need use motor starters for the pumps as i have no idea what size they are. Utilizing the signal from the latching relay.

If this device is going to be used to switch between the two pumps quite frequently do not recommend their use. The mechanics of some of the older designed devices have limit life in cycles. There are some newer designs that have higher life of cycles.

The jury is still still out on that will let you know when the newer designed ones fail.

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67model
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#11

Re: Latching Relay

07/31/2011 5:23 PM

If it is exactly a one motor or the other, from 2, choice, then you can get double motor contactors which are mechanically and electrically interconnected. This ensures that only one can operate at a time.

I suggest website schnieder-electric.com, brand name Telemecanique for good application information for motor control, including "interlocked contactors".
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67model (1); ikram shehzad (1); KJK/USA (1); ozzb (1); pnaban (3); PWSlack (1); rakesh_semwal (1); SimpleMind (1); Tornado (1)

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