Sonic Alert Digital Program Controller DCP301 - Manual (Page 31)

Chapter 3. MOUNTING
3-4
indicates that a function can be used.
The varister may become short-circuited when trouble occurs. Pay attention to
this when providing a varister on a controller.
■ Dust-proof cover
Use the dust-proof cover when using the controller in a dusty or dirty location, and to
prevent inadvertent operation.
Two dust proof-covers are provided, hard or soft, each with the following differing func-
tions.
Type Confirmation on Display Operation
Hard x
Soft
■ Noise generating sources and countermeasures
• Generally, the following generate electrical noise:
(1) Relays and contacts
(2) Solenoid coils, solenoid valves
(3) Power lines (in particular, 90Vac min.)
(4) Induction loads
(5) Inverters
(6) Motor commutators
(7) Phase angle control SCR
(8) Wireless communications equipment
(9) Welding equipment
(10) High-voltage ignition equipment
• If the influence of electrical noise cannot be eliminated, we recommend taking the
following countermeasures:
- Provision of a CR filters for fast-rising noise
Recommended CR filter: Model No. 81446365-001
- Provision of a varister for noise with a high wave height
Recommended varister: Model No. 81446366-001 (100V)
81446367-001 (200V)
Handling Precautions