Alternating Relay and Duplex Controllers manage pump runtimes.

Press Release Summary:

Rugged ARM Series microprocessor-based controllers evenly distribute runtime by automatically alternating lead and lag loads between 2 pump sequences. Devices include inrush delay to prevent both loads from energizing simultaneously, and five UL913 intrinsically safe low-voltage/-current control switch inputs. Integral device logic allows outputs to function if one input fails to open or close, while hand-off-automatic switches enable manual operation if needed.

Original Press Release:

Marsh Bellofram ATC Diversified Electronics Division Launches Integrated Alternating Relay and Duplex Controller Series

Newell, West Virginia, USA - The ATC Diversified Electronics division of Marsh Bellofram Corporation (, a member of the Marsh Bellofram Group of Companies, has announced the global market introduction of the ARM Series, a family of rugged, high-reliability alternating relays and duplex controllers, designed to ensure equal runtime of multiple load installations in pump sequencing, level control, lift station, motor protection and other industrial applications.

The Marsh Bellofram ARM Series incorporates a microprocessor-based controller which evenly distributes runtime by automatically alternating designated lead and lag loads between two pump sequences. The series also features an inrush delay, which prevents both loads from energizing simultaneously, thus significantly reducing line sag, while allowing for additional load capacity in the event of excess requirements. Units include five UL913 intrinsically safe low voltage/low current control switch inputs which are electrically isolated from the control voltage and load alarm contacts. Five LED indicators are included to confirm the functionality of the inputs. Incorporation of hand-of-automatic (H-O-A) switches allow for manual operation as needed.

Additional features include an integral alarm output, with alarm contacts that close when a control switch fails or system capacity is exceeded; control switch fault detection, which notifies the user of open and shorted control switch failures; and a test-and-clear switch, which verifies device function and resets the control switch fault detection algorithm as needed. The integral device logic of the ARM Series allows for outputs to continue their operation, even if one input fails to open or close. Special controls are also available upon customer request. Available mounting configurations allow for back or front panel mounting, as required. For more information about the ARM Series or other products available from Marsh Bellofram, visit

More from Thermal & Heating Equipment

All Topics