|[AMRadio] WE 303J|
manualman at juno.com
Thu Dec 17 13:43:57 EST 2009
I believe I have all the WECo relay information data sheets and/or a list
of models and specs. I saw them the last time I was pulling some data
information on WECo. transformers from my stash. I'll take a look later
On Thu, 17 Dec 2009 11:30:13 -0700 "JAMES HANLON" <knjhanlon at msn.com>
> I don't have the info on the 303J you are after, but John, K2TQN,
> gave you good advice. If you can find just one coil winding with
> your ohm meter, that's the one to work with. You should be able to
> find the normally closed contacts, they will measure very close to
> zero ohms. Monitor them while you ramp up voltage on the coil. The
> nominal coil operating voltage will probably be either 24 or 48
> volts. If you get up to 48 volts and the contacts have not opened,
> reverse the polarity of the voltage and try again. This relay will
> have a bias magnet, so you have to get the coil polarity right to
> make it operate. The relay should operate on substantially less
> voltage than its nominal rated value. It's operating time should be
> around 1 millisecond.
> Once the contacts have opened, you can use your ohm meter to find
> the "normally open" contact which at that point will be shorted to
> the swinger. The swinger will be attached to one of the two pins
> you've been monitoring, and the normally open contact will show up
> on another pin.
> The mercury-wetted switch inside is probably a WE 226D, judging from
> the size of the relay can. That switch is a single-pole, double
> throw switch that is of the "non-shorting" type. The swinger will
> break free (open circuit) from the normally-closed contact before it
> makes to the normally-open contact on its operate cycle. On its
> release cycle, it will similarly open up from the normally open
> contact before it makes to the normally closed contact. The 226D
> switch is rated for a maximum of 3 amps DC current, and it should
> switch up to a 50 VA load. Operated within its ratings, it should e
> good for more than a billion switcing cycles. It will not "bounce"
> or "chatter" on either operate or release. It should sustain more
> than 1000 Vac rms across its open contacts, although it shouldn't be
> used to switch that much voltage. I've used a similar relay to
> switch B+ on the order of 300 volts at around 0.05 amps for keying
> purposes with no problem. Insulation resistance of the
> open contact should be above 100 megohms. Resistance of the
> closed contact should be below 50 milliohms.
> Once upon a time, back in the 70's, I was the supervisor of the Bell
> Labs group that was responsible for the design of WE mercury wetted
> relays, just in case you are wondering.
> Hope this helps,
> Jim, W8KGI
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