- Galvanic isolation across input and output Protection against erroneous measurements due to parasitic voltages or ground loops
- No power supply required Saving costs since wiring is reduced and line influences are omitted
- Extremely compact design, 1- and 2-channel versions Only 6.3 mm DIN-rail per channel
- High accuracy No falsification of measured signal
- Protective Separation Protects service personnel and downstream devices against impermissibly high voltage
- Maximum reliability No maintenance costs
- 5 Years Warranty Defects occurring within 5 years from delivery date shall be remedied free of charge at our plant (carriage and insurance paid by sender)
 Datasheet |
| User Manual |
- Galvanic isolation across input and output Protection against erroneous measurements due to parasitic voltages or ground loops
- No power supply required Saving costs since wiring is reduced and line influences are omitted
- Extremely slim design, 1- and 2-channel versions Only 3.1 mm DIN-rail per channel
- Protective Separation acc. to EN61140 Protects service personnel and downstream devices against impermissibly high voltage
- Maximum reliability No maintenance costs
- 5 Years Warranty Defects occurring within 5 years from delivery date shall be remedied free of charge at our plant (carriage and insurance paid by sender)
| Datasheet |
| Ex- and UL-Instructions |
| User Manual |
- 1- and 2-channel versions Economical separation for standard applications
- Only 60 mm installation depth, 11.2 mm wide Can be installed in economical standard terminal boxes
- Galvanic isolation across input and output Protection against erroneous measurements due to parasitic voltages or ground loops
- High reliability and long-term stability New APT technology for signal processing
- Protective Separation acc. to EN 61140 Protects service personnel and downstream devices against impermissibly high voltage
- No power supply required Saving costs since wiring is reduced and line influences are omitted
- 5 Years Warranty Defects occurring within 5 years from delivery date shall be remedied free of charge at our plant (carriage and insurance paid by sender)
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Datasheet
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User Manual
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Passive Isolators (Loop-Powered Signal Isolators)
Passive isolators provide galvanic isolation between input and output without requiring an external power supply. They draw their operating energy directly from the existing current loop, typically a 0/4…20 mA signal. This isolates both circuits, prevents ground loops and protects control systems from interference and potential differences. Passive isolators are compact and optimized for DIN-rail installation inside control cabinets.
Questions & Answers on Passive Isolators
What is a passive isolator?
A passive isolator is a galvanic signal isolator that operates without an external power supply, using the energy of the input current loop.
Which signals can passive isolators handle?
They are designed mainly for standard current loop signals such as 0…20 mA or 4…20 mA, transmitting these signals with complete galvanic isolation.
Why are passive isolators used?
They eliminate ground loops, reduce interference and protect connected control equipment from potential differences and unwanted voltages.
Does a passive isolator require auxiliary power?
No. It operates solely with the energy extracted from the input current signal, simplifying installation.
How does a passive isolator affect the current loop?
The loop remains intact; the isolator introduces only a defined voltage drop that must be considered when designing the loop power budget.
Does a passive isolator affect measurement accuracy?
High-quality devices transmit the input signal with minimal deviation and offer very high stability over time.
How is a passive isolator mounted?
It is mounted on a DIN rail and inserted into the existing current loop using screw or spring terminals.
When is a passive isolator preferable to an active isolator?
Whenever only current-loop isolation is required and no signal scaling, amplification or conversion of other signal types is necessary.
What are the benefits of operating without auxiliary power?
Reduced wiring, fewer potential points of failure and increased operational reliability due to the absence of an additional power source.
What is the typical voltage drop of a passive isolator?
It is usually a few volts and is specified for each device type.
Can passive isolators amplify or scale signals?
No — they transmit the signal 1:1. For scaling or amplification, an active converter is required.
How does ambient temperature affect passive isolators?
Low temperature drift ensures stable performance even under varying cabinet temperatures.
Are there versions for very narrow installation spaces?
Yes, many models are designed with extremely slim housings, suitable for dense cabinet layouts.
What is the response time of a passive isolator?
Typically in the millisecond range, allowing rapid signal processing.