Tech. Explanations - Kendrion Binder

the technical background
Voltage
Release delay
Release time
Return time
Slow intermittent duty is the operating mode in
which the coil ON time is so short that the stabilised
coil temperature is not reached, and the coil OFF time
is so long that the solenoid cools down to its reference
coil temperature.
Current
Linear movement
Response delay
Travel time
Response time
5. Response and release times, operating
modes, temperature terms, insulation classes
5.1 Response and release times
Response delay (t 11 ) is the time between switching
on the energisation current and the plunger beginning
to move.
Travel time (t 12 ) is the time taken by the plunger to
move from its initial position to its end position.
Response (t 1 ) is the total of response delay plus
travel time.
Release delay (t 21 ) is the time between switching
off the energisation current and the plunger beginning
to move back.
Return time (t 22 ) is the time taken by the plunger
to move from its end position back to its initial
position.
Release time (t 2 ) is the total of release delay plus
return time.
The diagram above illustrates the characteristic oscillogram
with lines indicating voltage, current and movement
of a DC linear solenoid. This clearly shows the
composition of the response and release times. The
response times specified on the data sheets are reliably
reached at 70% of the magnetic force, the rated voltage
and with the solenoid at its operating temperature.
5.2 Operating modes
Continuous duty is the operating mode in which the
coil ON time is so long that the stabilised coil
temperature is reached.
Fast intermittent duty is the operating mode in
which coil ON time and coil OFF time alternate in a
regular or irregular sequence but the coil OFF times
are so short that the device cannot cool down to its
reference coil temperature.
5.3 Temperature terms
The ambient temperature (°C) is the average
temperature around the device.
The reference coil temperature (°C) of a solenoid
is the stabilised coil temperature in the non-energised
state for the intended application. In certain cases this
temperature may differ from the ambient temperature
if, for example, the solenoid is fitted to a part of a
machine operating at a higher or lower temperature.
Unless specified otherwise, the reference coil
temperature is +35°C.
The differential temperature (°C) is the difference
between the temperature of the device or a part
thereof and the temperature of the associated means
of cooling at the same time (or the surroundings in the
case of non-cooled solenoids).
The maximum stabilised coil temperature (°C) is
the maximum permissible temperature for the solenoid
or a part thereof. It is usually determined by the
thermal stability of the insulation used.
Air cooling is the case when the dissipation of heat
from the solenoid to the surrounding air is achieved by
way of, for instance, mounting the device on materials
with low or poor thermal conduction qualities, e.g.
wood, plastic.
Heat sink cooling is the case when the solenoid is in
contact with a metal surface enabling good thermal
conduction and most of the heat is dissipated via this
surface. In this situation the solenoid can be operated
with a longer coil ON time or, in certain circumstances,
with a higher voltage for the same coil ON time. The
relative humidity should be approx. 50% at 35°C.
Higher relative humidities are permissible at lower
temperatures.
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