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47DAC OPERATING MANUAL EM-9518-B Rev.4
1.7.6 WIRING ALARM OUTPUT (RELAY)
Two or four alarm contacts are output depending on the specified I/O option code.
IMPORTANT
• Connect load within the specifications.
• The mechanical lifetime of the relays is 5,000,000 operations.
• With inductive load such like an external relay or a motor, insert a CR circuit (for AC or DC power), a diode (for DC
power) or a varistor (for AC or DC power) in parallel to protect the contacts and eliminate noise.
I/O options code: 1, 7
I/O options code: 2, 8
15
16
17
18
19
20
HHa
Ha
Hc, HHc
La
LLa
Lc, LLc
H
output
LL
output
L output
HH output
15
16
17
18
19
20
Ha
(NO)
Hb
(NC)
Hc
(COM)
La
(NO)
Lb
(NC)
Lc
(COM)
L output
H output
NOTE
Example of contact protection circuit with inductive load
Power
47DAC
Inductive load
Varistor
RC
circuit
Diode
C
R
■
DC powered
Power
47DAC
Inductive load
Varistor
RC
circuit
C
R
■
AC powered
U
U
*
It is effective to connect a varistor across a load with the supply voltage 24 to 28 V, and across a contact with 100 to 200 V.
