The Mac3 3F Controls are a DIN socket mounted, adjustable under-voltage monitoring and protection relays intended for use in control panels.
Mod.22 is Single Phase.
Mod.33 is Three phase with additional phase loss protection.
Low voltage leads to increased current and excess heat generation in induction motors causing damage or reducing the life of coils and bearings. Low voltage may be caused by poorly functioning generators, and other temporary power systems, inadequate cable sizing especially temporary wiring or wiring in remote locations such as outbuildings, or poorly specified over-current protection allowing a circuit to be loaded by other appliances beyond it’s proper capacity. Hence under-voltage protection helps to protect important appliances from premature failure avoiding expensive down-time.
Both 3F Controls isolate the system if:
- The system voltage drops up to 2.5% of the set value for more than 2 seconds, or
- The system voltage drops more than 2.5% of the set value at all.
A 2 second delay, built into the relay, ensures temporary voltage drops in the electricity supply do not trip the system, while preventing potential pump damage should the condition continue.
The 3F Control Mod. 33 also monitors for phase loss and incorrect phase rotation. This can be due to wiring the phases incorrectly or issues arising from the supply itself, but either condition will cause the 3F Control Mod. 33 to isolate the system until the error is rectified.