Italian electrical network monitoring systems manufacturer Dossena is upgrading its DER3 differential current monitor to the DER4 (View all DER4 products) in both the DIN rail and door-mounting versions.
All technical details at a glance?
Check this quick product selection card:
Quick product selection card for Type B differential monitoring and insulation monitoring for industrial applications
EREA-Snelselectiekaart-Dossena-Industrie-2025-02-NL-FR.pdf
But what are the differences between the two in this update? Read on to find out.
Type A differential: DER3 upgraded to DER4
The DER3 family, suitable for general use (type A differential), is now being replaced by the DER4 family.
>Two-wire cable:
The innovation that stands out most is the wiring to the coil, which is now a 2-wire cable instead of 4-wire. This makes installation faster and easier, plus it reduces the risk of wiring problems.
>Time delay:
As with the older series, the new DER4 devices allow you to set not only the tripping threshold, but also a time delay. This will stop the occasional spike from causing a false alarm when you switch on the device.
>Multiple diameters:
The device can be used for medium to large installations (up to 1000s of amperes), depending on the diameter of the measuring coil that the relay is combined with.
Type B differential: DER3-DUAL upgraded to DER4B
The DER3-DUAL family is now being replaced by the DER4B series. This range is designed for differential monitoring in installations where there might be a DC component in the fault current (such as electric vehicle chargers and frequency converters).
>Detects AC and DC leakage currents:
The DER4B is the big brother of the DER4. On top of AC leakage currents, it also detects DC ones.
>Early warning alarm:
The new version also features an early warning alarm when the power supply is about to switch off.
>Just one coil: TBxxx
With this new generation DER4B, only one coil (TB80, TB110, TB180, …) is needed, which is connected with 2 wires, instead of the two coils with 4 wires each. This makes for a simpler and more reliable installation.
>Compact DIN rail version:
While the form factor of the door-mounting version is unchanged, the DIN-rail version is now half as wide: 3 DIN instead of 6 DIN.
>RS-485 link:
These devices are available in an RS-485 version, which allows you to link up to a building management system (BMS).
View all DER4 products for differential current monitoring.
Got any questions about our differential current monitoring products?
Useful:
- This quick product selection card gives you an overview of all technical specifications.
- Want to dive deeper? Check out this leaflet.
Don’t hesitate to get in touch. We’d be happy to help you find the right solution.