Quest Controls TELSEC MP1 User Manual page 13

3.4.4 Contact Closures
®
The TELSEC MP1 supports dry contact closures or wet contacts up to 65 VDC. A wet contact is an input
where there is an external voltage present. A dry contact has no voltage present and the MP1 provides
the sensing voltage. The detection point for determining ON/OFF status is greater than 2.8 VDC and less
than 0.8 VDC. There is no transition when the voltage is between these two values. Both wet and dry
input types are connected between the input terminal and a common terminal. For Wet inputs the
voltage must be between 0 VDC and up to +65 VDC. Negative voltages are not supported. Make sure to
define the input properly for "Wet" or "Dry" contact closures (see section 9.1) for proper operation.
Monitor Switch
Figure 5 - Wiring Contact Closures
©
Rev 3.0 9/15/22 - 8 - TELSEC MP1 User Guide