The AC-410 Series Phase Sequence Loss Monitor from the ATC Diversified Electronics division of Marsh Bellofram are plug in Phase Sequence and Loss Monitors that protect 3 phase refrigeration equipment from adverse line conditions such as:
PHASE LOSS (SINGLE PHASING): When any one phase drops to 83% or less of the adjustment setting of the AC-410 Series Phase Sequence Loss Monitor.
UNDER VOLTAGE (BROWN OUTS): When all three phase voltages drop to 90% or less of the adjustment setting of the AC-410 Series Phase Sequence Loss Monitor
PHASE REVERSAL (IMPROPER SEQUENCE): When the wrong sequence is applied to the equipment.
When any of the mentioned occurs, the internal control relay of the AC-410 Series Phase Sequence Loss Monitor drops out and a 3 minute delay-on-break time delay begins. This delay is used to lock out the compressor, allowing time for head pressure to equalize. When the delay has completed, the relay will re-energize provided all conditions are corrected and the external control voltage is present on terminals six (6) and seven (7). A green indicator glows when all line conditions are normal and a red indicator shows when the timer is in its delay.
