at last! my E57

[Siggi]

I think it looks all right!

But correct me if I'm wrong ... !

[orestis]

Hi freunde!

It's quite difficult for me to find a way to connect my to 380 V since I have to do same changes to the central board- of cource it will be done in the future, I hope soon.

@Wolfi, since then I thougt it would be easier to connect it to 24v as you told me, to make some rpms. But I found a company and told me the transformer costs 150 €!!

Have you got any idea for a cheaper solution?

[orestis]

Hi!

finally my was mounted on the base. I had this DEXION base for many years. On it was sitting a self-constructed siren. Before installing the I had to make it more steady and robust in order to assure the safety of the siren, so I fixed a metal plate 2mm width on the top, and large wooden base plates.

Of course ... - the most important- I still have to connect it

[Wolfi]

Hi Orestis !

Nice to hear from you again and congratulations for
your excellent done restauration work !

I`m a little wondering that such a simple transformer
will cost 150 €. That is much, much too expensive !!
You need a single phase low voltage transformer
primary 220 to 240 volts / secondary 24 to 42 V at
a rated current of about 5 - 6 amps. This results in
a transformer size of about 100 to 250 VA, such
transformers will cost here less than 50 €, new !

Don`t you have the possibility to purchase such a
transformer from second hand or a flea market ?
Last week, I visited a radio amateur`s flea market
and there were some transformers like this offered
for prices between 5 and 20 €.

I could have a look for it for the next radioamateur`s
market at October 21st, but what would shipping to
Greece cost ?

Ok, let`s see ...
best regards,

Wolfi

[orestis]

Wolfi thank you very much!

Maybe I didn't look in the right places. I went to electronics' markets and all prices that told me were about 150 - 180 EURO. Of cource I was asking about 220 to 24V, 9A. Maybe with less Amperes will be cheaper.

I was looking for a transformer also in Ebay, but no good... I believe this is the only chance for me to get something cheap...
(sent you a PN with an auction)

With how many rpms do you think the siren will run with such connection?

Thanks a lot for your help!

[Wolfi]

Hi Orestis !

Today I found a possible low voltage transformer at a
flea market ... further details in P.M. !

I think, rpms will depend on voltage and connection mode.
If you apply for example 30 volts in star mode wiring,
I assume it will run at approx. 200 - 300 rpm, in delta mode
probably up to 500 rpms, making a little grumbling sound ...

But ... always realize that a three phase asynchronous motor
cannot start for itself when applying only one phase. There
MUST be an initial kick, so that the rotor is able to run with
one or two phases.
Always check the current flowing, it must be < 9 amps
(maybe, at low voltage it will only be a few amps). When
current is flowing at about 20 to 50 volts, give the rotor a
little kick in its designated rotating direction. BE CAREFULLY
and do not try with bare fingers, but with a little wooden or
plastic stick or so.
Then, I think the siren will rotate ...

Have fun and best regards,
Wolfi

[orestis]

Oh, Wolfi thank you very much about your concern
!