TR250
12410-0701-03
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11 / 18
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2-wire, compensation of line-resistance:
To compensate the line resistance short-circuit the wires nearby the sensor and measure the line
resistance.
With 2-wire connection and a common line for all signals, all sensor measuring currents will be added on
the common line. Thus the value of the compensation line resistance RK must be calculated as follows:
RK=(n+1) x RL/2 (RL = line resistance of two wires, n = number of sensors)
We recommend using 2 or bettering 3 wires for each sensor.
Combination of sensor and Alarms (
AL/E
),
important:
Here it is programmed, which alarms
(=relays) are affected by the sensor. Select alarm with
▲/▼. Set switches alarm on or off (see red
LED at alarm-contacts). The LEDs of the activated alarms are alight.
Leave menu item with button Set
► when
E
is in display (on to next menu item)
Programming of Alarms 1-3 (
AL1/AL2/AL3
):
Select menu item with
▲/▼ until
AL1
and Limit (value) alternate in display, e.g.
AL1
and
130
for 130 °C.
Here it can be clearly read out, which limit is programmed and of which sensors the alarm is effected
(yellow LEDs sensor on).
Enter into programming with Set
►.
Set limit with
▲/▼. At sensors type
PtC
no limit can be programmed.
Hysteresis. Negative hysteresis = MAX-alarm, the relay switches at the programmed limit and
switches back after the temperature is below the limit by the value of the hysteresis. E.g. limit 130
°C and hysteresis -5 °C: Relay switches at 130 °C and back at 125 °C. Positive hysteresis
everything inverted = MIN-limit . At sensors PTC no hysteresis can be programmed.
Alarm delay
dAL
: An alarm is being suppressed for this time. Short exceeding of the limit does not
result in an alarm.
Switch-back delay
doF
: An alarm is switched off this time after the temperature is below the limit,
e.g. a cooling fan can cool down a transformer for this additional time to ensure, that it needn't be
started again after a short time.
Function of relays:
o
r
-closed-circuit current mode, relay is picked up in GOOD condition (=limit not exceeded)
and releases when the limit is reached. Advantage: Errors and malfunctions will normally
result in an alarm. Disadvantage: with switched off device and shortly after switching on the
supply voltage an alarm is reported. Disadvantageous when the supply-voltage of the
device is created by the monitored transformer.
o
A
-operating current mode. Relay is released in GOOD condition and picks up when the limit
is exceeded. No alarm when supply-voltage is off. This mode is applied normally with
heatings, fans or for tripping of transformers.
o
rL/AL
: Alarm switches interlocked. Reset only after the temperature is below the limit (+
hysteresis) and after switching-back delay time has passed.
Error: At
Err/SE
it can be programmed, if the relay switches at troubles (short-circuit or interruption)
at a sensor. (or error of device
Er3/4
). Select sensor with
▲/▼. Set ► switches sensor on or off
(yellow LED at the sensor input changes). LEDs of activated sensors light up. Leave menu item
with button Set
► when
SE
is in display (on to next menu item). We recommend to program this
error message for a pre-alarm (
Pr2
,
Pr3
and
Pr6
) or a relay that is not used for other purposes (
Pr1
and
Pr5
).
LEDs in Programming Mode
Sensor-programming
appropriate LED Alarm is alight
Alarm-programming
appropriate LED Sensor is alight
Err
, Error at Sensor
appropriate LED Alarm is alight