Frequently Asked Questions
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Why is there a voltage present at the terminals of the open contact of an IHP digital time clock.?
The new generation programmable time switches (CCT15720, CCT15721, CCT15722, CTT15723, CCT15850, CCT15851,CCT15852, CCT15853, CCT16650 and CCT15652) integrate the O-crossing technique. This is an electronic procedure enabling the circuit to be opened at zero current, which enables the electromechanical contact to be operated off-load.
This is used to avoid the inrush currents of certain loads, particularly lighting.
This solution involves a low leakage current traveling through the electronics which generates residual voltage at the contact terminals, even when open. This can cause problems when very low loads (small relays, LEDs, etc.) are operated, as the receiver may be "held on" by this spurious voltage.
Note:
For this type of application (low load), a conventional electromechanical programmable time switch should be used.
Is the CCT15725 available in 24v dc
Only available in 240v only
Why can't I measure a voltage on the time switch output contacts.
The time switches have a "volts free" contact which means that the contact is not connected internally to the time switch power supply.
The contact needs to be separately fed (usually linked across from the incoming live)
Instructions for Merlin Gerin timer CCT15837 or CCT15854
See the attached installation instructions for both timers.
Is the CCT15837 still available for Purchase?
No, the CCT15387 has been superceeded by the CCT15838. This only has 1 N/O contact.
How to program Timer CCT15854 Schedules?
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