Voltage Monitoring Relays and Electrical Equipment Protection
Single-Phase Voltage Relay with Thermal Protection ZUBR Dt 25/40 A
Price includes 24% VAT · excl. VAT 31.21 € – 38.06 €
ZUBR Dt is a single-phase voltage monitoring relay with thermal protection. It protects domestic and industrial electrical equipment against dangerous overvoltage, undervoltage and voltage deviations caused by neutral conductor failure. The voltage relay is installed inside an electrical distribution board and disconnects the load when the voltage exceeds the user-defined limits.
Heatline offers 25 A and 40 A models. ZUBR Dt is intended primarily for a standard 230 V mains supply with a sinusoidal voltage waveform. It is suitable for protecting household appliances, heating equipment, pumps, compressors, refrigerators and other voltage-sensitive equipment. Detailed settings and wiring diagrams are available in the manufacturer’s English ZUBR Dt web manual.
ZUBR Dt is a voltage monitoring relay, not an impulse surge protective device. It does not replace a Type 1 or Type 2 SPD but can be used alongside one as part of a coordinated protection system.
Product code: 50565060
Voltage realy main benefits
- overvoltage and undervoltage protection;
- protection against voltage deviations caused by neutral failure;
- built-in thermal protection;
- accurate True RMS voltage measurement;
- professional ProModel disconnection mode;
- adjustable upper and lower voltage limits;
- adjustable reconnection delay;
- digital voltage display;
- display correction within ±20 V;
- log for 50 fault events;
- non-volatile settings memory;
- load switching close to the voltage zero crossing;
- 25 A and 40 A models;
- installation on a 35 mm DIN rail.
How ZUBR Dt works
ZUBR Dt voltage relay continuously measures the voltage of a single-phase electrical network. The lower voltage limit can be adjusted between 100 and 210 V, and the upper limit between 230 and 280 V.
If the voltage falls outside the selected limits, the relay disconnects the load. Once the voltage has stabilised, power is restored after the user-defined delay.
The reconnection delay can be adjusted from 3 to 600 seconds. For refrigerators, heat pumps, air conditioners and other compressor-driven equipment, the manufacturer recommends a delay of 120–180 seconds.
Built-in thermal protection
ZUBR Dt monitors the temperature inside its enclosure. If the internal temperature reaches approximately 80 °C, overheating protection is activated and the load is disconnected.
Overheating may be caused by loose terminals, excessive load, an incorrectly selected conductor cross-section or a high temperature inside the distribution board.
The load is switched as close as possible to the voltage zero crossing. This reduces contact arcing and helps extend the service life of the power relay.
True RMS, ProModel and event log
True RMS provides an accurate effective voltage measurement even when the voltage waveform is distorted. The displayed voltage can be corrected by ±20 V when required.
ProModel takes account of both the magnitude and duration of a voltage deviation. This helps prevent unnecessary disconnection during short voltage variations that remain safe for the connected equipment.
Up to 50 fault events are stored in non-volatile memory. The log records the voltage at which the load was disconnected and any activation of the overheating protection.
ZUBR Dt or ZUBR D2?
| ZUBR Dt | ZUBR D2 |
|---|---|
| Heatline models rated at 25 A and 40 A | Heatline models rated at 40 A and 63 A |
| Thermal protection, True RMS and ProModel | Thermal protection, True RMS and ProModel |
| Log for 50 events | Log for 100 events |
| Three-module width | Two-module width |
| Economical choice for a standard 230 V mains supply | Newer and more compact model |
| Not intended for continuous operation from a modified sine wave source | Better suited to generators, inverters and UPS systems with an imperfect voltage waveform |
True RMS measurement does not mean that ZUBR Dt is suitable for continuous operation from a modified sine wave source. ZUBR D2 is recommended for this type of inverter, generator or UPS.
Models
| Model | Rated current | Permitted current for up to 10 min | Rated load | Power relay type |
|---|---|---|---|---|
| D25t | 25 A | 30 A | 5700 VA | electromagnetic |
| D40t | 40 A | 50 A | 9200 VA | polarised |
The operating and starting current of the load must be considered when choosing a model. If the load exceeds the relay’s rated current or has a high starting current, a suitable contactor must be used.
Installation
ZUBR Dt is installed inside an electrical distribution board on a standard 35 mm DIN rail. The device is 53 mm wide and occupies three standard modules.
A correctly rated circuit breaker must be installed upstream of the relay. The maximum conductor cross-section is 16 mm². Installation must be carried out by a qualified electrician according to the manufacturer’s wiring diagram.
The relay has an IP20 protection rating and is intended for installation inside a dry electrical enclosure. In humid or dusty environments, the distribution board must provide an appropriately higher protection rating.
Technical specifications
- Product type: single-phase voltage relay with thermal protection
- Manufacturer: DS Electronics
- Series: ZUBR Dt
- Electrical network: single-phase 230 V, 50 Hz
- Models: D25t and D40t
- Rated current: 25 A or 40 A
- Rated load: 5700 VA or 9200 VA
- Adjustable lower voltage limit: 100–210 V
- Adjustable upper voltage limit: 230–280 V
- Undervoltage disconnection time: up to 1.2 s
- D25t overvoltage disconnection time: 0.01–0.03 s
- D40t overvoltage disconnection time: up to 0.04 s
- Reconnection delay: 3–600 s
- Voltage measurement: True RMS
- Professional disconnection mode: ProModel
- Display correction: ±20 V
- Event log: 50 events
- Thermal protection activation: approximately 80 °C
- Operating supply range: 100–420 V
- Maximum conductor cross-section: 16 mm²
- Mounting: 35 mm DIN rail
- Width: 53 mm, three modules
- Dimensions: 53 × 85 × 66 mm
- Protection rating: IP20
- Weight: approximately 0.21 kg