Figure 9-2 Transient Suppression In Inductive Coils; Table 9-3 Coil Voltage Vs Resistor Voltage Rating - Honeywell UDC3300 Product Manual

9.6 Noise Suppression at the Source,
Inductive coils,
continued
102
Figure 9-2 is an illustration of transient suppression in inductive coils.
Figure 9-2 Transient Suppression in Inductive Coils
A.C.
supply
Additional protection may be provided by adding an RC circuit in parallel
with the MOV. This consists of a 220-ohm resistor in series with a 0.5
microfarad, 1000V capacitor. The power rating of the resistor will depend
on the voltage rating of the coil (see Table 9-3).
Table 9-3 Coil Voltage vs Resistor Voltage Rating
Coil Voltage
115V
230V
460V
550V
UDC3300 Limit Controller Product Manual
Continued
MOV
R
C
Resistor Voltage Rating
Inductive
load
20781
1/4 Watt
1 Watt
3 Watt
5 Watt
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