Honeywell DCP552 Mark II User Manual

Page 132

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7-33

C93 (time proportional output system)

C94 (time proportional output system)

0: Goes on again within time proportional cycle
1: Does not go on again within time proportional cycle
• This setting determines whether the output is to go on again after the result of a

PID computation has changed in a time proportional cycle (cycle time) and the
output has been turned off.

• The difference between the two settings is illustrated below.

C95 (voltage output control)

C96 (voltage output control)

In a voltage time proportional output driven by SSR, the

DCP552

must enter the

SSR rated input voltage (optimum striking voltage of arc).
The

DCP552

employs a newly developed variable output system that can output

optimum striking voltage of arc to accommodate multiple SSR drives. A suitable
current value is set on the

DCP552

to obtain optimum striking voltage of arc for

the internal impedance of the SSR. An equivalent circuit with related equations is
shown below.
• Description of symbols

(1) Settings

I

0

: set

DCP552

output current (range: 2 to 22mA)

V

0

: end-to-end load voltage (13.2V)

V

SSR'

: actual voltage input to SSR

V

SSR

: rated input voltage range for SSR (V

SSR/MIN

to V

SSR/MAX

)

V

SSR/MIN

: minimum SSR rated input voltage

V

SSR/MAX

: maximum SSR rated input voltage

Z

: internal SSR impedance

V

D

: internal SSR voltage drop (normally about 1 to 2V)

(2) Equivalent circuit showing connection of one SSR

Equations (1) and (2) below must be satisfied.
V

SSR/MIN

≤ I

0

× Z + V

D

≤V

0

Equation (1)

V

SSR'

≤ V

SSR/MAX

Equation (2)

(V

SSR'

= I

0

× Z + V

D

)

I
(V )

0

0

DCP552

SSR

V

SSR'

Z

V

D

When set to 0

20%

50%

40%

OFF

ON

PID computation

result

Cycle time

Cycle time

20%

50%

40%

OFF

ON

PID computation

result

When set to 1

Cycle time

Cycle time

Chapter 7. PARAMETER SETUP

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