H3CR-A-300 OMRON [Omron Electronics LLC], H3CR-A-300 Datasheet - Page 21

• Manufacturer Part Number: H3CR-A-300
• Description: Solid-state Multi-functional Timer
• Manufacturer: OMRON [Omron Electronics LLC]

Precautions (H3CR-A)
Note: The undermentioned is common for all H3CR-A models.
I Power Supplies
For the power supply of an input device of the H3CR-A@/-A@S/-AP ,
use an isolating transformer with the primary and secondary wind-
ings mutually isolated and the secondary winding not grounded.
Example: H3CR-A
The H3CR-A@/-A@S/AP’s power supply terminal 2 is a common ter-
minal for input signals to the Timer. Do not disconnect the wires on
terminal 2, otherwise the internal circuitry of the Timer will be dam-
aged.
Make sure that the voltage is applied within the specified range, oth-
erwise the internal elements of the Timer may be damaged.
G,
5, 6, 7
S,
Input device
R
2
Input
terminal
H3CR-A
Input terminal
5, 6, 7
G, S, R
10
2
Isolation transformer is required.
H3CR-A
2
10
Power supply
Solid-state Multi-functional Timer
I Input/Output
Relationship between Input and Power
Supply Circuits (except for H3CR-A8E)
The H3CR-A (except for H3CR-A8E) uses transformerless power
supply. When connecting a relay or transistor as an external signal
input device, pay attention to the following points to prevent short-cir-
cuiting due to a sneak current to the transformerless power supply. If
a relay or transistor is connected to two or more Timers, the input ter-
minals of those Timers must be wired properly so that they will not
differ in phase, otherwise the terminals will be short-circuited to one
another.
It is impossible to provide two independent power switches as shown
below regardless of whether or not the Timers are different in phase.
Incorrect
Correct
Contact or transistor for
external input signal
Input
terminal
Input
terminal
Input
terminal
Input
terminal
Input
terminal
Input
terminal
H3CR-A
H3CR-A
Short-circuit current
Power supply
Power supply
Power supply
B-129