HAT833 Series Three Power ATS Controller User Manual Page 48 of 56
14
NEL CONTROL
14.1
ILLUSTRATION
Non-essential load ---- NEL for short, which refers to load can be ramped off in prior when genset
power is undercapacity.
The controller can control the NEL1, NEL2 and NEL3 to trip separately. The order of the essentiality
is: NEL3 > NEL2 > NEL1.
14.2
AUTO OPERATION
When NEL auto trip is enabled:
If the genset power has exceeded the NEL trip value, after the trip delay, NEL1 will trip the earliest,
and then is NEL2, NEL3;
When NEL auto reconnection is enabled:
If the genset power has fallen below the auto reconnection set value, after the auto reconnection
delay, NEL3 will reconnection the earliest, and then is NEL2, NEL1.
Fig.5 – NEL Sequence
14.3
MANUAL OPERATION
If NEL manual trip input is active (earthed falling edge is active), NEL1 will trip without delay; If NEL
manual trip input is active again, NEL2 will trip; If NEL manual trip input is active the third time, NEL3 will
trip. During this process, the controller does not detect if the genset power has exceed the NEL trip
value or not.
If NEL manual reconnection input is active (earthed failing edge is active), NEL3 will reconnect
without delay; If NEL manual reconnection input is active again, NEL2 will reconnect; If NEL manual
reconnection input is active the third time, NEL1 will reconnect. During this process, the controller
