Heating current measurement
Measure and evaluate heating currents and use them for process reliability
The heating current measurement is an important addition to the functional scope of the controller.
- It displays the current flowing through the heating, regardless of the number of phases.
- It provides information about the status of the heating (total failure/partial failure when heaters are connected in parallel) and monitors the current value, taking into account a tolerance band.
- It monitors the status of the power controllers and reports an alarm if the heating controllers are permanently switched on (e.g. SSRs that are alloyed through, contactor “sticking”), which can result in damage to the heating due to overheating.
- It supports a variety of controller functions. For example, incorrect calculation of the control parameters can be prevented because no heating current is detected in the control zone.
Every Meusburger controller or control system is prepared for heating current measurement. There are 2 measurement methods (individual current measurement and total current measurement) that can be used depending on the series. Several current transformer types are available for the heating currents to be measured.
Individual current measurement
Each control zone has its own measurement input and is measured with its own current transformer. Depending on the heater used (single-phase heater, three-phase heater), up to three single-phase current transformers or one three-phase current transformer can be used per zone.
Sum current measurement
Multiple heating zones are measured with one current transformer and only require one measurement input on the controller. Therefore, an assignment of control zone and current transformer must be planned. Depending on the heaters used (single-phase heaters, three-phase heaters) and the phase distribution of the heaters, up to three single-phase current transformers or one three-phase current transformer can be used for each measuring input.the heating currents for each control zone are measured one after the other. The measuring process is controlled by the controller. The controller ensures that the heating current of each control zone is measured separately.
| Reglerbaureihe | Anzahl Messeingänge / Anzahl Phasen | Einzelstrom-messung | Summenstrom-messung | Hinweis |
|---|---|---|---|---|
| ETR 46 | 1 x einphasig | x | ||
| sysTEMP ETR 132 | Pro Modul 8 x dreiphasig | x | x | |
| sysTEMP ETR 112 | 2 x dreiphasig | x | Über CANSTI | |
| sysTEMP ETS 132 | 2 x dreiphasig | x | ||
| flexoTEMP DIO 16 CI | 1 x dreiphasig | x | Für die auf dem Modul projektierten Zonen | |
| flexoTEMP DIO 32 CI | 2 x dreiphasig | x | Für die auf dem Modul projektierten Zonen | |
| THYPO TP | x | Im Modul integriert, Messung rückwirkungsfrei auf Regelung. |
Compensation of mains voltage influences
Mains voltage measurement modules can be used to reduce the influence of mains voltage fluctuations on the measured heating current. The heating current displayed is corrected by calculation using the measured mains voltage.