Hb Alarm - gefran 650 Installation And Instruction Manual

5.6.2.

HB alarm

This type of alarm calls for the use of the current transfor-
mer input (I.CT1 / I.CT2), which is assigned to a control
output, from which the ON and OFF phases are considered.
The alarm signals changes in load draw, discriminating the
value of currents for current inputs I.CT1 and I.CT2.
The alarm is active if the rms current value:
• is below set value LOW.ON in the ON time of the of the
assigned control output,
• is above set value HIG.ON in the ON time of the of the
assigned control output,
• is above set value HI.OFF in the OFF time of the of the
assigned control output.
Single tests are disabled by setting a value of "0.0".
The HB alarm trips if one of the above setpoints is excee-
ded for the set TIME.
Each of the three conditions may indicate a problem in the
process managed by the assigned control output.
HB alarm tests are activated only with ON times of the assi-
gned output longer than 0.4 seconds.
The alarm resets automatically if the condition that caused
it is eliminated.
The load current is shown by parameters CURR1 and
CURR2 on the user configuration menu.
Note: ON/OFF times refer to the cycle time set for the con-
trol output selected in OUT.
During configuration, you have to indicate load type with
LoAd, specifying if it is a monophase load with only one cur-
rent transformer CT1 (MONO), a 3-phase star load no neutre
with CT1 and CT2 (STAR), or a 3-phase delta load with CT1
and CT2 (DELTA).
~
~
SSR
+
+
Out
logic
Figure 18 - HB alarm with monophase load
80208G_MHW_650-1250-1350_01-2017_ENG
CT
-
-
In
CT1
Controller
5. Examples and applicative notes
~
SSR
+ -
CT
~
SSR
+ -
~
+ -
Out In
logic CT1
Controller
Figure 19 - HB alarm with 3-phase star load without Neutral
~
~
SSR
+ -
~
SSR
+ -
+ -
Out
logic
Figure 20 - HB alarm with 3-phase delta load
A 3-phase load can be controlled by means of a logic output
connected in series to two SSR modules.
5.6.3. HB alarm calibration
Calibration is possible:
- by user calibration U.CAL = AL.HB (turning the selected
output on in OUT)
- as a function of the settable front key (but.1 for model 650,
but.1 or but.2 or but.3 for models 1250 and 1350);
to acquire the current value, the power in automatic or
manual must be > 10%; press the key to confirm the percent
value (set in parameter THR.PE) of the current value that is
saved in parameter LOW.ON.
5.6.4. LBA alarm
This alarm signals an interrupt in the control loop as a pos-
sible consequence of a sensor in short circuit, an inverted
sensor, or a load break.
It trips an alarm if the variable does not increase its value in
heating (or does not decrease it in cooling) when maximum
power is supplied for settable time LBA.TM.
If the parameter is set to LBA.TM = 0 the LBA function is
disabled.
CT
In
CT2
CT
Load
CT
In In
CT1 CT2
Controller
143