relay ly4nj 220/240vac

[XOKE]

Hi guys,
Today I tested a relay to switch between grid power and power inverter to feed a water pump (very small one 88 watts)
This water pump works fine with this power inverter, and I intend to use this for:
Every time I connect the inverter their power feed the water pump and when turn it down it works (water pump) with power grid.
But probably I made some mistake and damage the power inverter.
This how I connect it, anyone here use this relay or better one and cheap for this appliance?





These connections are right?
Please some help
Thanks

xoke

[bob g]

at a minimum you will need a dpdt relay

and even then you risk damage to the inverter should something stick
or break in the relay.

best to use a reversing contactor such as

http://www.ebay.com/itm/Fuji-Reversing-Contactor-4NC0G0-SC-05-w-Interlock-SZ-RM-OL-Relay-JEMLR-TR-0N-/300785075580?pt=LH_DefaultDomain_0&hash=item460830057c

you could strip away the lower overload relay, and use only a pair of contacts on each of the contactors

reversing contactors are both mechanically and electrically interlocked, and the contacts are separated sufficiently to keep from having catastrophic failures (grid to generator or grid to inverter crashes, where the grid always wins)

these reversing contactors are generally always 3 phase and are used to reverse motors, however all you need to do is reverse flow the wiring so to speak. just put the grid into the bottom of one contactor, the inverter into the bottom of the other, and connect the load to the jumpered top connections of both contactors.

this way the only way your load will connect is either to the grid or to the inverter, but not both under any circumstances.

while the rev contactor offered on ebay is larger than you need, it is a good one and will last forever.

one thing to keep in mind is the control coil voltage, commonly they are 24vac, 120, 240 and sometimes 480volt coils, (an there are a few other odd voltages and some dc ones as well)  so keep this in mind before you buy one. having said that the coils are generally replaceable with whatever voltage you want for a price of course.

most contactors are also rebuildable, should the time come you can replace the contact elements, springs and such for a reasonable price.

fwiw
bob g

[XOKE]

Hi,

thanks Bob G

I think that I´ll do it safe, very safe
shut one down and turn other on, switching manually.
cheap and safe

regards

[Mary B]

Or get a 30 amp automatic transfer switch

http://www.ebay.com/itm/T-30-WFCO-30-AMP-120-VOLT-AUTOMATIC-TRANSFER-SWITCH-/221116775532?pt=LH_DefaultDomain_0&hash=item337b963c6c

I have the older version of this one

http://www.ebay.com/itm/PowerMax-Furrion-30-amp-120-vac-automatic-transfer-switch-PMTS-30-rv-solar-iota-/251162953167?pt=LH_DefaultDomain_0&hash=item3a7a7a85cf

[OperaHouse]

If others are thinking of trying this, you have to use a 480V contact rated relay because you can have two 240V sources that are out of phase making a potential across the contacts of double the nominal voltage.   On an engineering forum I see this popping up a couple times a year with people trying to figure out why their relay relay went up in smoke.

[bob g]

there should be no condition where two sources come together at any time.  this is why i don't like having to shut out one source before going to another, its just too easy to forget and close in one before shutting out the other... the result is far worse than magic smoke in some cases.

A/B switchgear is about as bullet proof as it gets, however that is a manual proposition.

this is why i suggest looking into reversing contactors, being electrically and mechanically interlocked it is almost impossible to get a crossconnected train wreck.

bob g