I have a 220AC universal series wound motor I am trying to connect to a RF Remote Switch using relays and full bridge rectifiers.
I have come up with the following schematic:
The RF Remote Switch takes 220AC through the P-N connection and outputs it through L-N (UP) or L1-N (DOWN) depending on the selected direction on the remote control and it also has a stop button where no output is enabled. The switch seems to be correctly designed and has a small delay when changing from L-N to L1-N or vice versa.
The full bridge rectifiers are KBPC5010 (50A, 500V) and the DPDT relays are LY2NJ or LY2J.
R1 relay is used to control polarity when the L1 output is selected, and the R2 relay is used for dynamic braking through the R resistor.
The problem I encounter is that dynamic breaking seems to work fine when only operating the motor in the UP direction (L-N) and stopping, as the R resistor heats up; but it does not work when operating in the DOWN direction (L1-N). When the motor is receiving voltage through the L1 line and it is stopped, a visible spark comes out of the motor housing.
I think this is because deactivation of the L1 line causes the R1 relay to switch before the R2 relay (R1 activation is caused by L1, while R2 activation comes from the dual bridge assembly) and causes a change in polarity to the input of the motor before the dynamic breaking resistor path can be activated. What would be the correct way to avoid this from happening?