On 4/7/06, Mohamed Ismail Bari <izmile@gmail.com> wrote:
> Hi guys,
>
> I have designed a circuit with a relay to turn ON/OFF a 1.5HP motor (250V
> AC). The relay is energised with 6V and is wired to an opto isolator
> (MCT2E). The other side of the isolator is driven by PIC16F877. The problem
> is - when the relay is energised, the relay contact archs. This happens may
> be once in 5 times. "Sometimes" due to the arching the PIC gets reset.
> (Eventhough there is opto isolation!)
>
> I was thinking of trying a snubber but never seen one used for AC circuits.
> Furthermore, the load is inductive and it might cause damage to the
> capacitors. Any ideas on how to realiabily control it?

Let's go backward: 1HP = 746W (always talking in metric units system,
that's why have been invented)
So 1.5HP = 1.1kW
If you're runing on one phase 220V + nul is one way to solve the
problem (because your motor circuit should have a false phase
generation using either capacitors either inductors), if you're using
a tri-phase supply would be another way.
So what kind of motor do you have?

greetings,
Vasile

>
> Thanks,
> Ismail
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