Beckhoff KL2602 Series, Документация

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Commissioning
KL2602, KL2622, KL2634 29 Version: 2.4.0
4 Commissioning
4.1 Remarks for usage of relay terminals
Analyze operation conditions
It is extremely important to observe the technical specifications if fault-free operation is to be guar-
anteed.
If relays are to be used in a control system the expected operating conditions must be analyzed with great
care.
• Switching capacity, service life (operating cycles) and the number of switches per minute must be
considered. Any time that the stated parameters are exceeded, damage ranging from premature
contact ageing up to fused contacts can result.
• Appropriate protective circuits must be used to protect the relay contacts from excessive voltage peaks
such as can occur when switching inductive loads (contactors, motors etc.). This allows switching
frequencies nearly equal to those appropriate to resistive loads to be achieved.
• Arcing time when switching DC loads are significantly longer than those for comparable AC voltages
(zero crossing); material flow can result.
• If the terminal is used to change the direction of inductive loads, adequate dead-times during the
switch-over must be provided, in order to avoid temporary short-circuits.
Durability*
Fig. 16: KL26x2, KL2634 - Durability (*'not valid for KL26x2-0010)