Energy-saving switches, hybrid switch relays and network relays for building installations

This DOLD group covers three special devices for building installations. The energy-saving switch pairs a timer with a remote switch, so lighting can be shut off in a controlled way before the set time has run out. It also suits fans, dryers and other loads that rarely need to come straight back on after use, cutting both energy use and running costs.

The hybrid switch relay serves heating, ventilation, air conditioning and lighting circuits where strongly inductive or capacitive loads, such as energy-saving lamps, must be switched. On the IK 3070/200, a semiconductor makes the connection at the AC voltage zero crossing, then the relay contact carries the continuous current a few milliseconds later to keep losses low. At turn-off the sequence reverses, which keeps surge voltages, inrush currents and electromagnetic interference to a minimum.

Network relays (IK/SK 9078) disconnect supply voltage from a circuit once all connected consumers are off, a common choice for bedrooms and other rooms where electro-smog is a concern. Note that a network relay is not a means of safe isolation. Reliable cut-off also depends on the residual load: standby devices, interference capacitors and long cable runs can create reactive currents that keep the relay from switching off.

• Energy-saving switch: timer and remote switch in one device
• Hybrid relay for inductive and capacitive loads in HVAC and lighting
• IK 3070/200 combines zero-crossing semiconductor switching with a relay contact
• Suited to high switching capacity with long service life
• Network relay cuts supply to circuits in electro-smog-sensitive rooms
• Keep cables between network relay and consumers as short as possible