Chino EH3000 Series, Instructions Manual

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4. CONNECTIONS
4.5 Alarm Output Terminals

(4) Cautions on Connection
Remarks and references for connections are as follows.
Connect the load which is equal or less than the specification ( ) to the alarm output terminals.
After connections, the power for the buffer relay is applied to the alarm output terminals and an electric shock occurs if you touch these
terminals. Make sure to close and mount the terminal cover with a screw after the connection.
 
-marking on Alarm Output Terminals
•
Mount a contact protective element matching to the buffer
relay.
•
It is effective to mount the element at the coil side of the
buffer relay for preventing a wrong operation due to a light
load (refer to (3) Connections ‘a’ in the figure in
“Connection example for Form 1a1b contact mechanical
relay output”).
Mounting of Contact Protective Element Z
Remarks2
The alarm outputs of this product may become defective due to wrong operation, failures, abnormal inputs, or others. Take safety
measures separately before use if required.

Take Safety Measures
The alarm output of this product is by a Form 1a1b contact.
With the 1a1b contact output type, ‘a’ contact side and ‘b’
contact side may turn ON simultaneously on operation and
return.
Confirm operational conditions or others of load side fully
before use.

Caution on Contact Behavior Timing
•
Coil rating: Equal to or less than contact ratings of output
terminals
•
Contact ratings: Twice the load current or more
A relay with a built-in element for coil surge absorption is
recommended.
Mount an additional buffer relay if a buffer relay satisfying the
load rating is not available.
Selection of Buffer Relay
Reference1
Mount a contact protective element if a buffer relay with a
built-in element for surge absorption is not available.
The element is generally composed of C (Capacitor) and R
(Register).
<Reference values for C and R>
C: 0.01
μ F (Rating: About 1 kV)
R: 100 to 150 Ω (Rating: About 1 W)
Selection of Contact Protective Element
Reference2
Power supply Resistive load Inductive load
250VAC
100VAC
2.0A 1.0A
30VDC 2.0A 1.0A
* Minimum application load: 5 VDC, 10 mA (Reference
value)
Reference value of switchable lower limit. It may depend
on use conditions, environment conditions, and others;
therefore, check it under actual use conditions.
Contact Ratings of Alarm Output Relay
Remarks1