14
(3) Specifications for wiring
Item
Description
•
Contact rating of mechanical relay
outputs (both Form A and Form C
contacts)
Selection of buffer relay
•
Coil rating: less than the contact rating of the output terminals
•
Contact rating: more than twice the load current
A relay with a built-in coil surge absorption element is recommended. Add an
additional buffer relay if the buffer relay does not satisfy the load rating.
Selection of surge absorber and
mounting
•
Use an appropriate surge absorber element to protect the contacts if the
buffer relay does not already have one.
•
The MOS relay might burn out if a signal exceeding the contact rating is
applied, even momentarily.
•
To prevent malfunction caused by a light load, the most effective mounting
position for the surge absorber is on the coil side of the buffer relay (‘a’ in the
wiring diagram in section 3.7, (2)).
•
The surge absorber is generally composed of a capacitor (C) and resistor
(R).
Reference values for C and R
C: 0.01 F (rating about 1 kV)
R: 100 to 150 (rating about 1 W)
Azbil Corporation’s surge absorber is No. 81446365-001 (qty. 10).
Handling Precautions
The common terminal of each alarm output is separate from the others.
Power supply
Resistive load
Inductive load
100 Vac
0.5 A
0.2 A
240 Vac
0.2 A
0.1 A
30 Vdc
0.3 A
0.1 A
Minimum load
:
100 A
and 100 mVdc
