Can a P-frame breaker with a Micrologic A trip unit be upgraded to a P or H trip unit, and allow communication through Modbus?
If a Powerpact P-frame circuit breaker has a Micrologic A trip unit, what is needed to upgrade it to a P or H trip unit, and also allow communication through Modbus?
Applies to Powerpact P-frame circuit breakers with factory-installed Micrologic A trip unit, and that are unit-mounted, or are I-line.
Does not apply to P-frame circuit breakers that use a rotary handle, are motor operated, or are drawout.
When a Powerpact P-frame circuit breaker is manufactured with a Micrologic A trip unit, typically a communication module is not included in the breaker. Also, since the A trip unit only measures amps (not volts), there is no connection to measure voltage.
To add Modbus Communication capability: Assuming the existing breaker does not have a Breaker Communication Module (BCM), a BCM must now be added internally to the circuit breaker. Note that the BCM will require a 24Vdc power supply.
To change from Micrologic A to the P or H Trip Unit: The Micrologic A trip unit will be removed and replaced by a Micrologic P or H trip unit. Note that the P or H trip unit will require a 24Vdc power supply (if not existing).
To allow measurements of volts and amps: An External Voltage Sensing device must be added to the breaker.
IMPORTANT: The 24Vdc power supply for the BCM must be separate from the 24Vdc power supply for the P or H trip unit. In other words, two 24Vdc power supplies will be required.
Here is the summary of parts and quantity needed:
Qty (1) Breaker Communication Module (BCM), catalog number S64205, see instruction bulletin, 48049-338-01.
Qty (1) Micrologic P or H trip unit:, choose either catalog number S163A (5.0P), S164A (6.0P), S173A (5.0H), or S174A (6.0H)
Qty (1) External Voltage Sensing module (If neccessary), catalog number S64203, see instruction bulletin, 48049-339-01.
Qty (2) 24Vdc output power supplies, choose either catalog number 685823 (24-30Vdc input), 685824 (48-60Vdc input), 685825 (125Vdc input), 685826 (110-130Vac input), 685827 (200-240Vac input), or 685829 (380-415Vac input), see instruction bulletin, S1A80373.
In order to make the above changes, the breaker must be de-energized and open with the cover removed. There is also significant setup and testing to be done. In other words, the procedure is complex. While there is not a restriction on who can perform the work, we do recommend enlisting Schneider Electric Field Services due to their experience and expertise.
For help with Micrologic trip units and modbus communications for Masterpact and Powerpact P and R circuit breakers, consult instruction manuals:
Powerpact P, R, and Masterpact NW, NT Micrologic™ 5.0P and 6.0P Trip Units, see 48049-137-05
Powerpact P, R, and Masterpact NW, NT Micrologic™ 5.0H and 6.0H Trip Units, see 48049-330-03