H3CA

14

Safety Precautions

How to Change Operation Mode

Operate the pushbuttons of the thumbwheel switch, located at the

leftmost position on the front panel to set the operation mode. Eight

operation modes (A, B, C, D, E, F, G, and H) are selectable and the

selected operation mode is displayed in the operation mode display

window.

How to Change Time Unit and Rated

Time

Operate the pushbuttons of the rightmost thumbwheel switch to

select the desired time unit. Seven time units (0.1 s, s, 0.1 m, m,

0.1 h, h, or 10 h) are selectable and the selected time unit is

displayed in the time unit display window. The desired rated time is

specified by operating the three thumbwheel switches in the middle

of the front panel. The range of rated time is 001 to 999 for each unit.

Time Unit and Rated Time

!CAUTION

1. Do not change the time unit, rated time, or operation mode while

the timer is in operation. Otherwise, the timer may malfunction or

be damaged. Be sure to turn off the power supply to the timer

before changing the timer unit, rated time or operation mode.

2. Note that output will be generated in C, D, E, G, or H mode even if

the rated time is set to 000. No output will be generated in A, B, or

F mode.

Connecting the Operating Power

Supply

The H3CA-8

@ contains a capacitor-drop power circuit. Use a

sinusoidal power supply with a commercial frequency. Do not use

power supplies with a high frequency component (such as inverter

power supplies) for Timers with 100 to 240-VAC specifications. Using

these power supplies can damage internal circuits.

The power supply connections to the H3CA-A and H3CA-FA can be

made without regard to polarity for both AC and DC power supplies;

just connect to the specified terminals (2 and 10, or A1 and A2).

When connecting a DC power supply to the H3CA-8 or H3CA-8H,

however, the polarity must be connected as indicated.

Although there is a wide range of power connectable to the H3CA-A

and H3CA-FA, be sure that there is no inductive voltage or residual

voltage applied to the timer power supply terminals (2 and 10, or A1

and A2) when the power switch is turned OFF. (Inductive voltage can

be generated in the power supply line if it is placed in parallel with

high-voltage or power lines.)

A DC power supply can be connected if its ripple factor is 20% or

less and the mean voltage is within the rated operating voltage range

of the Timer.

Connect the power supply voltage through a relay or switch in such a

way that the voltage reaches a fixed value at once or the Timer may

not be reset or a timer error could result.

H3CA-8 and H3CA-8H Timers with AC specifications are equivalent

to capacitor loads. When switching the Timer power supply with an

SSR, use an SSR with a withstand voltage of twice the power supply

voltage.

Since the H3CA-8 and H3CA-8H Timers of AC specifications

externally discharges a part of internal energy when the power is

turned OFF, it may malfunction if an extremely sensitive relay is used

with the following sequence circuit.

If such a malfunction occurs, change the circuit configuration as

shown below on the right side.

Time unit

Rated time

0.1 s

0.1 to 99.9 s

s

1 to 999 s

0.1 m

0.1 to 99.9 m

m

1 to 999 m

0.1 h

0.1 to 99.9 h

h

1 to 999 h

10 h

10 to 9,990 h

Note: The operation mode is fixed to "A" for H3CA-8H.

The characters are yellow.

Remaining time display

The remaining time is displayed

as a decreasing percentage

between 0% and 100%.

Time unit

selector

Time unit display

window

0.1 s, s, 0.1 m

0.1 h, h, 10 h

Rated time

selector

Rated time display

window

001 to 999

Note: The characters are yellow.

T/b

X/a

T/b

X/a

X/a

If malfunction

is expected.