Datasheet

H3CR-A
23
Safety Precautions (H3CR-A)
Refer to Safety Precautions for All Timers.
Note: The following precautions apply to all H3CR-A models.
Power Supplies
For the power supply of an input device of the H3CR-A use an
isolating transformer with the primary and secondary windings
mutually isolated and the secondary winding not grounded.
The H3CR-A’s power supply terminal 2 is a common terminal for
input signals to the Timer. Do not disconnect the wires on terminal 2,
otherwise the internal circuitry of the Timer will be damaged.
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-
circuiting due to a sneak current to the transformerless power supply.
If a relay or transistor is connected to two or more Timers, the input
terminals 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.
S,G, R
5, 6, 7
2
10
2
H3CR-A
Power supply
Isolation transformer is required.
Input device
Input
terminal
Correct
H3CR-A
Power
supply
Input
terminal
Input device
10
2
2
Incorrect
Isolation
transformer
S,G, R
5, 6, 7
5, 6, 7
G, S, R
10
2
H3CR-A
Input terminal
AC or DC
Power Supply
Power supply
H3CR-A
H3CR-A
Power supply
Incorrect
Correct
Short-circuit current
Contact or transistor for
external input signal
Contact or transistor for
external input signal
Input
terminal
Input
terminal
Input
terminal
Input
terminal
Power supply
Input
terminal
Input
terminal
Contact or transistor for
external input signal
H3CR-A