X20 system modules • Digital output modules • X20DO2633
X20 system User's Manual 3.10
1095
4.15.6.9 External fuses
The following protective circuit must be used for safe operation:
Protective circuit
Value
For the supply lines
Fuse
T 10 A
For the outputs
Fuse
Melting integral I
2
t ≤ 78 A
2
s when tp = 10 ms
With an inductive load
Varistor
1)
e.g. varistor with 275 V
RMS
at 240 VAC
For the supply voltage
Line filter
2)
Attenuation ≥40 dB at 150 kHz, effective range up to 5 MHz
1)
See also section 4.15.6.13 "Operation with inductive loads" on page 1096
2)
Meeting the limit values specified in the standards EN 61131, EN 55011 and EN 55022 (each Class A) requires installation of a line filter in the 240 V supply
line. Line filters such as the Schaffner FN
2412‐8‐
44 can be used.
If periodic ground transients occur on the supply lines (as can occur with upstream inverters), it is necessary to use an asymmetric filter that keeps these
types of changes in potential below a few volts (e.g. "Sinus Plus" from Schaffner) in addition to the symmetric filter.
4.15.6.10 Derating
The derating listed below must be applied for the current:
Legend:
Horizontal installation
Vertical installation
O
ut
pu
t c
ur
re
nt
[A
]
Ambient temperature [°C]
0
2.5
1.875
25
35
-25
60
50
4.15.6.11 Operating principle
The digital output module was designed for phase control of resistive and and inductive loads. The triac outputs
do not have short circuit protection. The integrated open-circuit detection makes it possible to recognize defects
on the load or the cabling (see 4.15.6.12 "Open line detection" on page 1095).
The module is equipped with internal zero-crossing detection. Zero-crossing detection is the basis for a software
PLL that generates 200 times the zero-crossing frequency. The output signal of the PLL is the base timer for the
PWM outputs in both digital and analog mode.
Upon detection of lost periods or periods that are too short, control to the outputs is cut until the PLL is tuned
correctly. The tuning procedure can take several seconds. In addition, the "ZeroCrossingStatus" bit is set and the
error LED enabled (valid frequency range for the supply is 45 to 65 Hz).
Information:
The jitter of the output signals generated by the PLL and communication can reach 0.5%.
4.15.6.12 Open line detection
The module is equipped with open-circuit detection. Note that open-circuit detection only works when the output
is enabled. An open-circuit will not be detected if the output is turned off.
In addition, open-circuit detection is restricted or doesn't work at all for inductive loads. This depends on the induc-
tance of the load and should be determined beforehand, if necessary.
Summary of Contents for X20 System
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