Isolating transformers are used for the electrical isolation of circuits in order to reduce the dangers resulting from accidentally touching earthed and live parts simultaneously. Isolating transformers can be used to satisfy the protective measure "protective separation". The connected equipment is safely isolated from the power supply network and must not be earthed. Isolating transformers are subject to DIN/VDE 0570/2-4/IEC61558/2-4 Part 1. The following max. nominal values apply:
•Input voltage: 1000 V
•Frequency: 500 Hz
•Output voltage: 1000 V (no-load and load)
•Power:
oSingle-phase transformers: 25 kVA
oThree-phase transformers: 40 kVA
Isolating transformers must be marked with the symbol to distinguish them from transformers for other applications.
Single-Phase Isolating Transformers to
VDE 0570/2-15/IEC61558/2-15
Protective winding between primary and secondary winding. Secondary with symmetrical connection for monitoring insulation.
•Power range 3.15 – 8 kVA
•With ± 5% taps for matching to mains voltage
•Frequency 50/60 Hz
•Output 230 V (with centre tap)
•Circuit li0
•Impedance voltage 3%
•No-load current Io < 3% of the rated current
•Inrush current surge max. 12 x IN
•Insulation class ta=40°C/B
•Thermostatic switch for acoustic or visual signal in case of impermissible heating
•Class of protection I
•Type of protection IP00
•(Suitable for installation up to IP23)