Excellent Value 120vac DPDT 30-Amp Relay

Tom_M wrote:

smkettner wrote:
I like the small cover.
OK it is twice the price but 50a rated.

http://www.ebay.com/itm/NEW-50A-DPDT

Nice relay but coil voltage is 120 volt DC. Adding a diode to the coil voltage may work.

I think most of the control modules with delay have the diode.

brulaz wrote:

Tom_M wrote:
I purchased one of these from Grainger

120 VAC 30 amp DPDT power relay

If I'm reading the specs right, the spring held NC contacts on this only have a 3A rating. Guess you need the strength of electromagnet to hold the NO contacts contacts closed to get the 30A rating?

Good catch. I must have assumed that the NC and NO ratings would be the same. I used this relay to transfer between inverter and shore/generator power. My 300 watt inverter is connected to the NC contacts so I lucked out.

WARNING. If you need 30 amps for both the NC and NO contacts, don't buy this one.

I would like to lay eyesight on what's inside a "Progressive Dynamics" transfer switch. The relay.

Yes this relay is "Old School (like me)"

But it makes a rolling-on-the-floor joke out of those .250" Faston connector relays as is depicted above. Like comparing a Wiha screwdriver to a Glorious Revolution Hero Factory No 32, screwdriver.

My primary objective is to Make It - Install It - Forget It

Utter reliability.

And NO and NC contacts need to be mused over. Shore power demands NC and guess what? NC contacts are "The Weakest Link". Or are you trying to convince reality that a generator normally supplies more amperage to your rig than a power pedestal?

Relay voltage threshold chatter is only a problem if amperage is broken and remade in the power contacts. Are you trying to tell me you spin down a generator with power load circuits loaded down?

The relay CONTACT area mm sq of the large relay dwarfs that of a plug-in relay. Or does anyone want to argue the point that the duty-cycle ability of a tiny relay equals that of a large relay? Quicksilver was built in the years following the outfitting of the Kelley II. I DID break-down and clean the power contacts with De-Oxit D100 the last visit (whether they needed it or not).

Meanwhile I am going to order some relays. And Yes, I do use SCR and solid state DC relays. Try and find one that lasts 30-years :)