Kamstrup MULTICAL 403 Ultrasonic Heat and Cooling Meter

Overview

The Kamstrup MULTICAL 403 is a static energy meter that works on the ultrasonic principle and can be configured as a heat meter, a cooling meter or a combined heat/cooling meter. It consists of a calculator, an ultrasonic flow sensor and a matched pair of Pt500 temperature sensors, and is intended for thermal installations where water carries the energy: apartments, villas, multi-family buildings, offices and small industry. The meter programme spans nominal flow qp 0.6 to 15 m³/h, and the calculator handles temperatures from 2 to 180 °C.

Seven Star LLC supplies the Kamstrup MULTICAL 403 to MEP contractors, building owners and district cooling customers in Oman and the GCC, with engineering support in Muscat. In a climate where cooling dominates the energy bill of most buildings, metering chilled water per apartment, shop or office floor is the fairest way to allocate cost and the first step to finding units that consume more than they should.

Measurement Principle

Thermal energy is the product of the water volume passing through the circuit and the temperature difference between supply and return. The flow sensor of the Kamstrup MULTICAL 403 measures volume with ultrasonic transit time: sound pulses sent along the measuring tube with and against the flow arrive at slightly different times, and the difference is proportional to velocity. There are no moving parts, so the sensor is not affected by magnetite or wear, and it keeps its calibration over the service life.

The calculator of the Kamstrup MULTICAL 403 reads the two Pt500 sensors, works out the temperature difference and integrates the energy, which is shown in MWh, kWh or GJ. Kamstrup quotes a typical flow sensor accuracy of ±(1 + 0.01 qp/q) % and a typical calculator accuracy of ±(0.15 + 2/ΔΘ) %, both inside the EN 1434-1 limits. When set up as a cooling meter, the unit registers energy when the return is warmer than the supply; in combined mode it accumulates heat and cooling energy in separate registers according to the measured temperatures.

Engineering Design of the Kamstrup MULTICAL 403

Threaded flow sensors of the Kamstrup MULTICAL 403 are made of hot-forged, dezincification-resistant brass CW 602N, while flanged sizes use stainless steel 1.4308. The transducers are stainless steel 1.4404, the measuring tube is PES with 30 % glass fibre and the O-rings are EPDM. The flow sensor is rated IP68 and suitable for PN16 and PN25 systems, and the calculator is IP54 for indoor installation at 5 to 55 °C. For media colder than the surrounding air, or above 90 °C, the calculator should be wall-mounted on its bracket rather than on the flow sensor, which keeps condensation away from the electronics.

Power can come from a D-cell lithium battery with a lifetime of up to 16 years, a 2 x A-cell pack, a C-cell IoT battery or a 230 VAC or 24 VAC/VDC supply module. A SuperCap backup bridges short power interruptions on the mains modules. Many parameters of the Kamstrup MULTICAL 403 can be set on site with the front keys, including flow sensor position in the inlet or outlet pipe, energy unit, primary M-Bus address, target dates and radio on or off, which reduces the number of meter variants a contractor needs to stock.

Key Features

The Kamstrup MULTICAL 403 combines legal-for-trade energy metering with flexible communication:

• One meter can be ordered as a heat meter, a cooling meter or a bifunctional heat/cooling meter.
• Ultrasonic flow sensor with no moving parts and a dynamic range qp:qi of 100:1.
• Low pressure loss, from 0.03 bar to a maximum of 0.14 bar at qp depending on size.
• Programmable data logger with intervals from one minute to one year and a standard depth of 20 years, 36 months, 460 days and 72 hours.
• Seven- or eight-digit LCD with 8.2 mm digits and selectable MWh, kWh or GJ units.
• Plug-in modules for wired M-Bus, Wireless M-Bus, linkIQ, NB-IoT, Modbus RTU, Modbus TCP, BACnet MS/TP, BACnet IP and analog outputs.
• Two pulse inputs for additional water meters, with configurable cold water leak detection on input A.
• Info codes for missing supply, low battery, disconnected or short-circuited sensors, air in the flow sensor and wrong flow direction, with an info logger holding the latest 50 changes.

Industrial Applications

The most common use of the Kamstrup MULTICAL 403 in the Gulf is chilled water sub-metering. Residential towers, mixed-use developments and shopping centres connected to a central chiller plant or a district cooling network install one meter per tenant on the fan coil or air handling unit branch, and read all meters through M-Bus or Modbus into the building management system. The combined heat/cooling version also covers buildings with both chilled water and domestic hot water or heating loops, such as hotels, hospitals and labour accommodation.

Facility managers use the Kamstrup MULTICAL 403 minute logger to check delta-T performance, which is often the hidden reason a chiller plant runs more pumps than designed. Seven Star LLC supplies the Kamstrup MULTICAL 403 to projects in Muscat, Duqm, Sohar and Salalah, together with the Kamstrup data sheet and advice on module, power supply and sensor cable length. For larger plant-room energy metering, Kamstrup also offers the MULTICAL 603 calculator for use with separate flow sensors.

Technical Specifications

The values for the Kamstrup MULTICAL 403 below come from the combined MULTICAL 303 and 403 data sheet FILE100003587 (edition 06.2024):

How to Order

To request a quotation for the Kamstrup MULTICAL 403, send Seven Star LLC the design flow per branch, pipe size, heat or cooling service, supply and return temperatures, the BMS protocol and the number of meters. Our Muscat team will confirm the meter configuration, advise on stock and lead time for Oman and the GCC, and provide the official Kamstrup data sheet for consultant review. Related energy meters on our site include the pFlow E3R LoRaWAN heat meter, the pFlow E5 ultrasonic energy/BTU meter and the Dynasonics UHC-120 thermal energy meter.