Ground Transformer?

[Harry Muscle]

I'm gonna be installing a big 250VA transformer in a plastic case and I'm
wondering if I should ground the metal body (the sheets of iron that the
wires are wrapped around) or just leave it ungrounded? Is it standard
practice to ground a transformer, or does this affect it's performance (or
would it maybe even short it)?

Thanks,
Harry

 

[John Popelish]

I'm gonna be installing a big 250VA transformer in a plastic case and I'm
wondering if I should ground the metal body (the sheets of iron that the
wires are wrapped around) or just leave it ungrounded? Is it standard
practice to ground a transformer, or does this affect it's performance (or
would it maybe even short it)?

One of the failure modes on overload is a short between windings and
core, so I normally ground the core, so that if this happens it blows
the primary fuse. Otherwise, the only effect this has is a very
slight reduction of effective capacitance between primary and
secondary.