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User Manual Digital Heat Regulators
English
Set point (set or operating point)
• The set point is the value at which the appliance has to intervene to maintain the
measurement controlled at the required level.
Differential (or hysteresis)
• The differential is the maximum permitted variation from the set point for
the measurement controlled prior to the intervention of the appliance.
• This is usually set in such a way as to prevent rapid oscillations in the
measurement around the set point from causing frequent start-ups and
shutdowns of the appliance or the driver connected to it.
Direct action
• A regulator acts in
direct
mode when it
limits the measurement as this increases.
A typical example is a refrigerator: the
increase in temperature corresponds to
an increase in the refrigeration power
produced, with a view to reducing the
temperature
Reverse action
• A regulator acts in
reverse
mode
when it limits the reduction of the
measurement controlled.
For example, in a heating system, the
reduction in temperature
corresponds to an increase in heat
production
Neutral or dead zone (“dead-band”)
• This indicates an interval of values around the set point in which the measurement
regulated may oscillate without the activation of any output. It is normally used in
the appliances in which there is a strong inertia of the system, as a result of which
the set point may be exceeded even after the driver has been switched off or to
prevent the overlap of a heating and cooling action.
Around the neutral zone, no
output is activated. Outside the
neutral zone, the instrument
operates in
direct
mode if the
measurement controlled
increases, and in
reverse
if it
decreases.
GLOSSARY
Set
D
ON
OFF
Set + Diff
Temperature
Direct Mode
Set � Diff
R
ON
OFF
Set
Temperature
Reverse Mode
Set - Diff (R) - ZN
R
ON
OFF
Set
Temperature
D
Set + Diff (D) + ZN
Neutral Zone Mode
ZN
ZN
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User Manual Digital Heat Regulators
English
PWM operation (in proportion to time)
• This is a neutral zone type of operation in which the relays are activated
periodically in impulse mode
(the interval can be set, see the
output menu).
The PWM procedure modulates
the power in accordance with the
position occupied by the
measurement within the
differential (the further we move
away from the set point, the more
the power increases).
Important: we advise against using this method to drive compressors,
due to the very close distance between start-up and shutdown.
Direct operating mode [PRO=0]
• In this mode, all the outputs
operate in
direct
. The values
of set point 1
[ST1]
and
differential 1
[DF1]
have
to be set. Hysteresis is to the
right of the set point. If both
outputs are used, the
hysteresis for each output is
equivalent to half the
differential. In this case,
output 1 will be activated when the measurement controlled reaches the value
[ST1]+[DF1]/2
, at which point output 2 will be deactivated.
Reverse operating mode [PRO=1]
• In this mode, all the outputs operate in
reverse
.
The set point 1
[ST1]
and differential 1
[DF1]
values have to be set.
Hysteresis is to the left of the
set point. If both outputs are
used, the hysteresis for each
output is equivalent to half the
differential. In this case,
output 1 will be activated
when the measurement
controlled reaches the value
[ST1]-[DF1]/2
, at which point
output 2 will be deactivated.
Set - Diff (R) - ZN
R
ON
OFF
Set
Temperature
D
Set + Diff (D) + ZN
PWM Mode
ZN
ZN
Set 1
D
ON
OFF
Diff. 1
PRO=0 mode
OUT 1
Set 1
D
ON
OFF
Diff. 1
OUT 1
D
OUT 2
1 output
2 outputs
Set 1
R
ON
OFF
Diff. 1
OUT 2
R
OUT 1
2 outputs
Set 1
R
ON
OFF
Diff. 1
OUT 1
1 output
PRO=1 mode
En
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