Switching voltage refers to the maximum signal voltage that the switch module can safely maintain. Switching voltage is defined from channel-to-ground and from channel-to-channel. Channel-to-ground is the voltage potential between the signal line and the grounded chassis. Channel-to-channel is the voltage potential between any pair of signal lines within the switch module. This voltage includes voltages across open relay contacts, as well as voltages between adjacent connection terminals.
Note   CE compliance marking for measurement and control devices requires compliance to the IEC 61010-1 standard. Switch modules intended for high voltage signals (> 60 VDC / 30 Vrms) are rated for Installation Categories as defined in this standard. Installation Categories describe the acceptable transient overvoltages and fault protection necessary for safe operation. Refer to the Read Me First: Safety and Electromagnetic Compatibility document for more information on Installation Categories.