Super Systems AC20 User Manual

Page 84

ERROR MESSAGES

OVERRANGE, UNDERRANGE AND TEMPERATURE

OVERRANGE, UNDERRANGE AND TEMPERATURE
INPUT LEAD BREAKING DETECTION

INPUT LEAD BREAKING DETECTION

The device is capable to detect a fault condition on input
variables (OVERRANGE or UNDERRANGE or TEMPERATURE
INPUT LEAD BREAKING).
When an error is detected the error code is shown (flashing) on
the upper display as follows:
a) Prhi

Sensor input out of range (OVERRANGE).
It is detected when:
- mV is the primary controlled variable and its

value is greater than 1515 mV;

- CP or DP is the primary controlled variable and its

value is greater than 1303 mV.

(Greater than 200 mV if “O2” is configured as

primary control variable)
b) PrLo Sensor input out of range (UNDERRANGE).

It is detected when:
- mV or O2 are the primary controlled variable and its

value is less than -15 mV.

- CP or DP is the primary controlled variable and

its value is less than 997 mV.

c) t.OPn Lead breaking detected on temperature input.

NOTE:

NOTE: if this error is detected, the instrument

operates as in presence of a temperature input
OVERRANGE.

d) tchi

Out of range detected on temperature input.

e) COFt Out of range detected on carbon monoxide input.

NOTE:

NOTE: if this error is detected, the CO value is

forced to 20.

NOTES:

NOTES:
1) When "CP" or "DP" is the controlled variable and an error from

a) to d) is detected, the device acts as described at "Special
output features" (see page 49).

2) When "mV" is the controlled variable and the error a)

(OVERRANGE) is detected, the "Main" output is forced to 0
and the "Secondary" (if configured) is forced to 100%.
The alarms and analog retransmissions operate as in presence
of the maximum measurable value.

3) When "mV" is the controlled variable and the error b)

(UNDERRANGE) is detected, the "Main" output is forced to
100% and the "Secondary" (if configured) is forced to 0.
The alarms and analog retransmissions operate as in presence
of the minimum measurable value.

4) When "mV" is the controlled variable the errors from c) to e)

are displayed only without affecting the control action.

On OVER-RANGE on remote setpoint measurement is