General Requirements for Commercial Heat Energy Metering Devices and Units
Commercial metering units for heat energy are installed in specially designated premises.
The asset holder of the premises is obliged to provide access for the installation, operation, and control over the readings of the heat meters and/or heat control equipment.
The requirements for the heat metering devices and units are based on the necessity of recognizing them as commercial equipment and ensuring minimal expenses for their procurement, installation and operation.
These requirements include the following:
- mandatory inclusion of the device in the State Register of Ukraine;
- protection from unauthorized interference in the work of the devices and the whole unit in general;
- minimum number of calculation parameters which are registered and which are required for calculations of the heat energy consumed;
- minimum number of sealed places in the metering unit, therefore, the lowest possibility of distorted readings. Is ensured, in particular, by the construction being single-block;
- autonomous power sources (from batteries) with an operational period of at least 5-6 years or an indication of time to signal duration of disconnection from an external power supply;
- compliance with the normative period of time between calibrations (depends on the meter type); and
- inability for the flow resistance of the metering object to significantly increase.
Choosing the metering unit requires attention to the range of parameter changes of the heat carrier in the object that must be measured.
The limits of acceptable relative errors for heat energy commercial meters while measuring heat energy consumption, heat carrier consumption and its temperature, the measurement of operation time and idle time are all defined by the project and must comply with the requirements of DSTU EN 1434:2006 “Heat Meters”.
The heat metering unit should be designed, installed and serviced by the heating utility and may be implemented in the form of:
- dispatched remote control system;
- tele-mechanical control system; or
- control sub-system as part of an automated dispatched control system (ADCS) or automated system for control of the heat supply technological process (ASCTP).
When multiple secondary devices such as the calculator are present, they are installed in a separate cabinet or separate section of the general cabinet. When using a one-piece secondary device, you can install it beyond the cabinet or in the general cabinet with the automated control devices.
The water meters, initial consumption converters, thermal converters, secondary one-piece devices installed openly or in the general cabinet, as well as separate cabinets (separate sections of the general cabinet) must be sealed.