Lovato DMED111 Single-Phase Energy Meter 40 A RS485

Lovato DMED111 single-phase DIN rail energy meter, 40 A direct

The Lovato DMED111 is a single-phase energy meter occupying one DIN rail module, wired directly up to 40 A without a current transformer. It measures active energy in class 1 and reactive energy in class 2 and has an RS485 serial interface. Seven Star LLC supplies the DMED111 in Oman and the GCC as an independent supplier in Muscat.

It is the smallest of the Lovato DMED energy meters. Sub-metering of a single-phase load, such as a tenant, a pump house or an air-conditioning unit, is its job; for three-phase feeders look at the DMED300T2 or other three-phase models.

DMED111 technical specifications

How the DMED111 measures energy

The meter measures voltage and current directly on the live conductor and integrates active and reactive energy. Because no current transformer is needed, the wiring is simply line in and load out through the fixed terminals, which accept up to 10 mm². The measurement range is defined by the transitional current of 0.5 A and the maximum of 40 A, below which the meter starts at just 20 mA.

The RS485 port allows the energy readings to be collected by a supervisory system, while the meter keeps its own register. Check the protocol documentation with the supplier before planning the integration.

Where the DMED111 fits

Typical use is cost allocation, with a DMED111 on each single-phase tenant or sub-feeder and a master on the main incomer. Within the Lovato range the DMED111MID version exists for billing applications and other single-phase and CT-connected meters appear in the same catalogue group, while three-phase measurement moves to DMED300T2 and the DMG power analysers.

DMED111 selection checklist

• Confirm the circuit is single-phase and the current never exceeds 40 A
• Check supply voltage lies in 93 to 264 V
• Decide whether a MID-certified meter is needed for billing; consult the MID variant instead
• Plan RS485 wiring and addressing for the supervisory system
• Check space: only one DIN module
• Verify ambient temperature below +55 °C inside the panel

Installation and commissioning of the DMED111

Snap the meter on a 35 mm rail, connect line and neutral and the load. Torque the terminals to 1.5 Nm. Keep the RS485 pair separate from power cables and terminate the bus at the last device. Compare the reading against a clamp meter on a steady load to verify installation. There is no routine maintenance; periodic checks of terminal tightness are enough.

Typical DMED111 applications in Oman and the GCC

In commercial buildings, labour accommodation, mosques, small workshops and remote kiosks, single-phase meters let operators split an electricity bill between tenants and identify heavy HVAC loads. High panel temperatures are common in outdoor cabinets, so the +55 °C limit should be checked.

Practical notes on metering with the DMED111

Specify the meter at the design stage together with a small isolator or breaker ahead of it, so that it can be replaced without shutting down the whole board. Label each meter with its tenant or load and record the first reading when the circuit is energised, because the register cannot be reset by the user once billing has begun. Where the load profile is very low, such as a standby circuit that draws only a few milliamperes, remember the 20 mA starting current: the register will not move below it, so very light loads are under-recorded.

Reactive energy is reported in class 2, which is enough to see whether a tenant is running at a poor power factor, though not for contractual metering. For fiscal billing, ask for the variant approved for it. Keep spare units on hand for projects with many meters, since a failed meter in a rented building often needs replacement the same day.

When several meters share one RS485 line, give each a unique address, keep the same baud rate on all of them and avoid star wiring. A shielded twisted pair with the screen earthed at one end is the usual practice, and a terminating resistor belongs at each end of the bus. Fault-finding is simple: if one meter is silent, check its address and wiring before replacing it.

Information to send with an RFQ for the DMED111

• Part number DMED111 and quantity
• Voltage system and maximum load current
• Whether MID or a billing approval is needed
• Communication requirements
• Panel ambient temperature
• Delivery location

Site conditions in Oman for the DMED111

Electrical rooms and outdoor panels in the Gulf often operate well above the 25 °C reference temperature used in many catalogues. Before you finalise the DMED111, compare the expected panel temperature with the operating range and any output derating stated in the manufacturer documentation, and leave the recommended clearance above and below the device for convection. Supply quality also varies between sites, so confirm the input voltage range, frequency and any requirements for protection on the supply side.

Where the device feeds or monitors critical loads, plan how faults will be signalled to the control system and how a replacement can be installed quickly. Keeping one spare DMED111 per site and recording its settings helps maintenance teams in Oman restore service with minimum downtime.

Documents and quotation

Send the part number DMED111 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.