Lovato PMV10A440 Phase Loss and Sequence Monitoring Relay

PMV10A440 voltage monitoring relay: decoded part number

The PMV10A440 is a three-phase monitoring relay from Lovato Electric that protects motors and equipment from phase loss and incorrect phase rotation. It is self-powered from the monitored supply and occupies only one DIN module, which makes it easy to add to existing panels.

Decoded: PMV10 is the model name of the phase-loss and phase-sequence relay in the PMV voltage monitoring family, and A440 is the ordering suffix for the 208 to 480 V range stated in the catalogue entry. Other family members such as the PMV20A575 and PMV50A575 are listed separately by the manufacturer for other voltage classes and functions.

Technical specifications of the PMV10A440

Values are from the Lovato Electric catalogue entry for PMV10A440. The relay does not monitor under-voltage, over-voltage or asymmetry.

How the PMV10A440 works

The relay measures the three line voltages and checks that all three phases are present and that they follow the right rotation. Under normal conditions the output relay is energised. If a phase is lost or the sequence is reversed, the relay de-energises within a fraction of a second and drops the contactor coil or alarms the control system.

The relay recloses automatically once the fault clears and the hysteresis of 5 % is satisfied. The LED shows that the relay is powered and whether it has tripped.

Phase monitoring is especially useful for pumps and compressors, where reverse rotation can damage seals and impellers, and for equipment moved between sites, where connections may be swapped.

Fit in the system and related Lovato Electric parts

It can be used in series with a motor starter, in the control circuit of the contactor, or as an input to a PLC. Other PMV models such as the PMV20A575 or PMV50A575 add voltage-level monitoring.

• PMV20A575 and PMV50A575 for extended voltage monitoring
• PMV45NA480, another member of the PMV family
• Contactors from the BF series to be controlled
• Motor protection breakers from the SM1P series

Selection and ordering checklist for the PMV10A440

Before ordering the PMV10A440, settle the following points so that the right variant is quoted:

• Supply voltage between 208 and 480 V AC
• Required functions: phase loss and sequence only
• Contact rating of the control circuit
• Mounting on 35 mm DIN rail with 17.5 mm space
• Whether an automatic reset suits the process

Installation, commissioning and maintenance of the PMV10A440

Connect L1, L2 and L3 to the relay terminals and wire the changeover contact in series with the starter coil or to an alarm input. Use conductors from 0.2 to 4 mm² and tighten to 0.8 Nm. Check the phase sequence with a phase indicator before energising.

Test by briefly removing a phase fuse with the load off and verify that the output relay drops.

• Check the LED indication during routine rounds
• Test the trip function after panel modifications
• Inspect terminals
• Replace if the contact life is exceeded

Typical applications in Oman and the GCC

Phase monitoring is a low-cost protection for pumps, compressors, cranes and any drive that must not run single-phase or backwards. In Oman and GCC sites supply interruptions and generator changeovers are common, and a monitoring relay prevents a mis-phased supply from starting machines.

Because the relay is self-powered, it needs no auxiliary supply, and so is straightforward to retrofit in older motor control centres.

When specifying a monitoring relay, remember that it only detects the faults it was built for. The PMV10A440 does not measure under-voltage, over-voltage or asymmetry, so where supply quality is poor, for example on long overhead feeders or weak generator supplies, a relay with those functions or a separate protection may be needed. It also does not replace a motor protection breaker or overload relay; use it together with them. For quotations, tell us whether the relay is to drop a contactor coil directly or to signal a PLC, since the load on the 8 A changeover contact differs.

Variants related to the PMV10A440

Related monitoring relays in the Lovato Electric catalogue:

Information to send with an RFQ for the PMV10A440

To quote the PMV10A440 quickly, please send:

• Part number PMV10A440
• Quantity
• System voltage and frequency
• Functions required
• Control circuit voltage and load
• Delivery destination and date

Site conditions in Oman for the PMV10A440

Low-voltage switching and protection devices in Oman often sit in motor control centres and outdoor panels where internal temperatures are high for much of the year. When you select the PMV10A440, check its rated values at your real ambient temperature, as stated in the manufacturer documentation, and confirm the coordination with upstream protection and with the motor or load it serves. Short-circuit levels differ from site to site, so verify the breaking capacity required at the point of installation.

Standardising ratings and coil voltages across a project reduces the number of spare part numbers that need to be stocked. Keeping a small stock of the PMV10A440 and recording settings such as trip ranges or ramp times shortens repair work during a breakdown.

Documents and quotation

No datasheet file is attached to this page. Send us the part number and we will confirm which official documents are available for your application.

For a quotation on the PMV10A440, send the part number or article number, quantity and the delivery destination in Oman or the GCC. Seven Star LLC is an independent supplier based in Muscat and confirms availability and lead time per request.