3-2
■ Sources of electrical interference and countermeasures
• The following noise generation sources are generally presumable.
(1) Relays and contacts
(2) Solenoid coils and valves
(3) Power lines (especially those carrying more than 90Vac)
(4) Inductive loads
(5) Inverters
(6) Motor rectifiers
(7) Phase angle control SCR
(8) Wireless communications equipment
(9) Welding machines
(10) High voltage ignition devices
• If the source of noise cannot be removed, take the following measures.
• Use a CR filter to suppress fast-rising noise.
Recommended CR filter : Model No. 81446365-001
• Use a varistor to suppress high-amplitude interference.
Recommended varistors : Model No. 81446366-001 (for 100V)
81446367-001 (for 200V)
Handling Precautions
Varistors must be handled carefully as they become defective if they are
short-circuited.
Chapter 3. INSTALLATION AND MOUNTING