18
LT 90 Owners Manual
2015
If the alarm LED is on, an alarm has taken place
To see the kind of alarm, the max (min) reached temperature and
alarm duration do as follows:
1. Push the Up or Down key.
2. On the display the following message is shown:
“HAL”
for high temperature alarm (
“LAL”
for the minimum
alarm), followed by the
Maximum (minimum) temperature.
Then the
“tiM”
(
tiM
e) message is displayed, followed by the
“Duration”
in h.mm.
3. Then the instrument displays the temperature once again.
NOTE1:
if an alarm is still occurring the “tim” shows the partial
duration.
NOTE2:
the alarm is recorded when the temperature comes back
to normal values.
1. Hold the SET key pressed for more than 3s, while the recorded
alarm is displayed. (The rSt message will be displayed)
2. To confirm the operation, the “rSt” message starts blinking
and the normal temperature will be displayed.
Push and immediately release the
SET
key: the
display will show the Set point value;
Push and immediately release the
SET
key or wait for 5
seconds to display the probe value again.
1. Push the
SET
key for more than 2 seconds to change the Set
point value;
2. The value of the set point will be displayed and the “˚C” or
“˚F” starts blinking;
3. To change the Set value push the or arrows within 10s.
4. To memorise the new set point value push the
SET
key again
or wait 10s.
To change the parameter’s value operate as follows:
1. Enter the Programming mode by pressing Set and keys
for three seconds. (the “˚C” or”˚F” LED start blinking)
2. Select the required parameter. Press the
SET
” key to display
its value.
3. Use “
UP
” or “
DOWN
” to change its value.
4. Press “
SET
” to store the new value and move to the following
parameter.
To exit:
Press
SET + UP
or wait 15s without pressing a key.
NOTE:
the set value is stored even when the procedure is exited
by waiting the time-out to expire.
1. Keep pressed for more than 3 s the and keys.
2. The “
POF
” message will be displayed and the keyboard will
be locked. At this point it will be possible only to see the set
point or the MAX o Min temperature stored.
3. If a key is pressed more than 3s the “POF” message will be
displayed.
5.1 HOW TO SEE THE ALARM DURATION AND MAX
(MIN) TEMPERATURE
5.2 HOW TO RESET A RECORDED ALARM OR ONE
THAT IS STILL OCCURRING
6. MAIN FUNCTIONS
6.1 HOW TO SEE THE SETPOINT
6.2 HOW TO CHANGE THE SETPOINT
6.3 HOW TO CHANGE A PARAMETER VALUE
6.4 HOW TO LOCK THE KEYBOARD
6.5 TO UNLOCK THE KEYBOARD
7. PARAMETERS
REGULATION
DISPLAY
ALARM
8. ALARM SIGNALS
Message
Cause
Outputs
“LA”
Minimum temperature alarm
Outputs unchanged.
8.1 ALARM RECOVERY
9. DEFAULT SETTING VALUES
Label
Name
Range
°F Level
Set
1
r
P
0
7
1
S
U
÷
S
L
t
n
i
o
p
t
e
S
Hy
Differential
0,1
25.5°C/ 1
255°F 10
Pr1
ALL
Minimum temperature
alarm
-50.0°C
Set/-58°F
Set 120
Pr1
Keep pressed together for more than 3s the and keys, till
the
“Pon”
message will be displayed.
Hy Differential:
(0,1 ÷ 25,5°C / 1÷255 °F) Intervention differential for
set point. Fan Cut IN is Set Point Minus Differential (Hy). Fan
Cut OUT is when the temperature reaches the set point.
CF Temperature measurement unit:
°C
=Celsius;
°F
=Fahrenheit.
WARNING
: When the measurement
unit is changed the SET point and the values of the parameters
Hy, LS, US, Ot, ALU and ALL have to be checked and
modified if necessary).
rES Resolution (for °C)
: (in = 1°C; dE = 0.1 °C) allows decimal
point display.
dLy Display Delay:
(0 ÷20.0m; risul. 10s) when the temperature
increases, the display is updateed of 1°C/1°F after this time.
ALL Minimum temperature alarm:
(-50.0 ÷ SET°C; 58÷230°F
when this temperature is reached the alarm is enabled and
fan will shut off.
AFH Differential for alarm recovery:
((1÷45 °F) It sets the value
above the alarm value for alarm recovery.
Probe alarm “
P1
” starts some seconds after the fault in the related
probe; it automatically stops some seconds after the probe restarts
normal operation. Check connections before replacing the probe.
Temperature alarms “
HA
” and “
LA
” automatically stop as soon as
the thermostat temperature returns to normal values.
Alarms “
EA
” and “
CA
” (with i1F=bAL) recover as soon as the
digital input is disabled.
Alarm “
CA
” (with i1F=PAL) recovers only by
switching off and on
the instrument.
E.T.C. Guide
Reference
