A
Adam Tenenbaum
Guest
Hi,
I'm trying to help diagnose a problem; the application is a simple
power relay switching a ~10 Ohm heating element load at 120VAC/60 Hz.
I was surprised to see significant charring on the relay contacts, as
the relay is rated for 30A. Everything I have read about the topic
(i.e. in this group + elsewhere) suggests that this effect only really
happens with inductive loads. Is it possible that a normal resistive
load could cause high enough inrush currents to char these relay
contacts? If so, I'd appreciate advice for selecting appropriate
values for the resistor/cap (without having a scope available to track
dv/dt).
Thanks,
Adam
I'm trying to help diagnose a problem; the application is a simple
power relay switching a ~10 Ohm heating element load at 120VAC/60 Hz.
I was surprised to see significant charring on the relay contacts, as
the relay is rated for 30A. Everything I have read about the topic
(i.e. in this group + elsewhere) suggests that this effect only really
happens with inductive loads. Is it possible that a normal resistive
load could cause high enough inrush currents to char these relay
contacts? If so, I'd appreciate advice for selecting appropriate
values for the resistor/cap (without having a scope available to track
dv/dt).
Thanks,
Adam