Lovato P5ME3PS0250 Moulded Case Circuit Breaker 250 A

Lovato P5ME3PS0250 moulded case circuit breaker, 250 A electronic trip

The Lovato P5ME3PS0250 is a three-pole moulded case circuit breaker rated 250 A with an electronic trip unit. The overload setting runs from 100 to 250 A and the short-circuit setting from 150 to 2500 A, and the breaking capacity reaches 100 kA at 240 V and 50 kA at 380 to 415 V. Seven Star LLC supplies the P5ME3PS0250 in Oman and the GCC as an independent supplier in Muscat.

In the code, P5ME is the electronic moulded case breaker family, 3 the number of poles and 0250 the rated current. The catalogue also lists four-pole versions such as the P5ME4PS0250 and other current ratings from 40 to 800 A in the same series. The meaning of the letters PS is not stated in the data table, so confirm the trip unit version in the catalogue when ordering.

P5ME3PS0250 technical specifications

Electronic trip settings on the P5ME3PS0250

A thermal-magnetic breaker has fixed or narrowly adjustable curves; the electronic unit of this breaker separates the overload and short-circuit settings. The overload threshold can be set from 100 to 250 A, so the same breaker fits feeders with different loads, and the short-circuit threshold from 150 to 2500 A gives room for selectivity studies. A low setting protects cable, a high one rides through motor starting.

The 150 A lower limit of the short-circuit setting is below the highest overload setting, so check the settings are consistent: the short-circuit pick-up has to stay above the overload setting plus the maximum motor starting current of the downstream load.

Temperature derating of the P5ME3PS0250

The rated current of 250 A applies at 40 °C. In an enclosure at 50 °C the data sheet allows 234 A, at 60 °C 220 A and at 70 °C 205 A. In Gulf switchrooms and outdoor kiosks, board temperatures of 50 to 60 °C are common, which means the practical rating is about 220 to 234 A. Allow for this when selecting the overload setting.

Where the P5ME3PS0250 fits

As a feeder breaker for sub-distribution boards, a main for small motor control centres or the incomer for a motor of 110 kW class on a 400 V supply. The family continues with the P5ME3PS0100, P5ME3PS0160, P5ME3PS0400 and P5ME3PS0630 for other currents. Downstream, motor protection breakers such as the SM1P2500 and contactors such as the BF2510A230 form the final branches.

P5ME3PS0250 selection and ordering checklist

• Load current and cable rating, then derate for panel temperature
• Prospective fault current vs 50 kA at 415 V and lower values at higher voltages
• Selectivity with upstream and downstream devices
• Three or four poles, depending on the earthing system
• Cable lugs for M8 terminals and torque 14 Nm
• Space for 105 x 160 x 86 mm and a 2 kg weight

Installation and maintenance of the P5ME3PS0250

Fix with screws to the backplate or mounting plate, tighten terminal bolts with a 6 mm Allen key to 14 Nm and use lugs matched to the cable. Set the overload and short-circuit knobs per the protection study and record them. Operate the breaker periodically, since it is rarely switched, and test it with a primary injection test as part of acceptance testing. Thermography at full load can reveal loose lugs.

Typical P5ME3PS0250 applications in Oman and the GCC

250 A feeders supply motor control centres, chiller plants, workshops, ventilation boards and camps. In large installations in Oman and the GCC, coordination with upstream protective devices and fault level at 415 V is the main design task.

Commissioning the electronic trip of the P5ME3PS0250

Settings should come from a short-circuit and selectivity study, not from the nameplate. A typical starting point for a feeder is the overload knob at the cable or load current, say 200 A, and the short-circuit knob at a value that sits above the largest motor starting current in the downstream circuit but well below the minimum fault current at the end of the cable, which ensures that a fault at the far end still trips quickly. Record both knob positions in the panel documentation, together with the date and the engineer.

Because the unit weighs 2 kg and has M8 terminals at 14 Nm, installation needs proper lugs, a torque wrench and a rigid backplate. Check the busbar or cable supports so the weight of heavy cables does not bear on the terminals. After the first month under load, retorque and thermographically scan, since new cable terminations settle. The 25,000 mechanical and 10,000 electrical operations are far beyond what a feeder breaker normally sees, so ageing is mostly a question of heat and dust.

Information to send with an RFQ for the P5ME3PS0250

• Part number P5ME3PS0250 and quantity
• Load current and voltage
• Fault level at the board
• Poles required
• Panel temperature
• Delivery location

Documents and quotation

Send the part number P5ME3PS0250 and we will confirm the documents available for it, such as the technical data sheet, wiring diagram and instruction sheet, together with availability and lead time.

Seven Star LLC is an independent supplier in Muscat and is not an official channel of the manufacturer. Share the quantity, delivery location and project reference with the request and we will answer with a formal quotation.