What happens to Feature 2B (Time Delay Normal to Emergency N>E) and Feature 3A (Time Delay Retransfer to Normal E>N) if Feature 34A or 34B (Inhibit transfer) inputs are active in a Group 5 controller?

Feature 34A - Opening of the contact will prohibit transferring to the normal source
Feature 34B - Opening of the contact will prohibit transferring to the emergency source

Below are the simulations that were done to observe the operation of Feature 2B & Feature 3A when Feature 34 inhibit inputs are active.

TRANSFER NORMAL TO EMERGENCY

• When 34B Contact Closed > Initiate Transfer N>E > TD N>E Countdown Running > Open Contact 34B > TD N>E Countdown Still Running > After Countdown Transfer Inhibited
• -When 34B Contact Open > Initiate Transfer N>E > TD N>E No Countdown > Transfer Inhibited

• When 34A Contact Closed > Initiate Transfer E>N > TD E>N Countdown Running > Open Contact 34A > TD E>N Countdown Still Running > After Countdown Transfer Inhibited
• When 34A Contact Open > Initiate Transfer E>N > TD E>N Countdown Running > After Countdown Transfer Inhibited
• When 34A Contact Open > Initiate Transfer E>N > TD E>N Countdown Running > Close Contact 34A > Switch successfully retransfer to Normal

Released for: Schneider Electric Thailand