|Posted: Mon May 28, 2018 5:00 am Post subject: Is the OVP 5 A CB supposed to trip when I switch off the
At 08:49 PM 5/27/2018, you wrote:
It is not directly protecting the contacts of the relay.Â The reverse EMF never touches the contacts of the relay.Â It is preventing the reverse EMF from allowing the contacts to bounce which causes the contacts to arc.
This is a myth . . . the coil collapse suppression
diode is demonstrably responsible for a DELAY in
the first opening of the relay's contacts . . .
but no significant effect on SPREADING VELOCITY
of those contacts. All other effects equal,
spreading velocity is a strong controlling factor
for arcing at the contacts during the opening
Contacts bounce only on closing . . . which
is a strong factor along with inrush currents
that control tendencies to weld contacts
together. When we were exploring options for
controlling the landing gear pump motor, a
driving factor in relay/switch selection was
the closing the circuit on a very low static
resistance i.e. inrush probably on the order
of 100 Amps.
Bob . . .
|- The Matronics AeroElectric-List Email Forum -|
Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:http://www.matronics.com/Navigator?AeroElectric-List