| There are many
applications where safety is very critical and it is important to
use electrical equipment which ensures that dangerous machine
movement cannot occur when a fault is detected with the moving
contacts during the cycle which the fault is indicated. The ABB
Type N & NL 4 and 8 pole relays are designed with "Positive
Guided" contacts and fulfill the regulations or standards shown. |
The relays can
provide positive safety for the N.O. and N.C. contacts which
assure that
the N.O. contacts will not close before any N.C. contact opens.
Therefore, if one of the contacts weld due to abnormal conditions
in the control circuit, the other contacts will also remain in the
same position as when the welding occurred. This means that the
open contacts must maintain an air distance 0.5mm when the coil is
energized at 110% Vc or when it is de-energized.
UL File No: E39231 (N & NL) |
