Emerson 20/20 Manuel D’Utilisation
2 – 1
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.8.5153
Section 2 • Installation Recommendations
Proper Wiring Sizing
• Always size wire gauges as specifi ed by the National
Electrical Code (NEC) for electronic control devices.
• For improved noise immunity, install one size larger
wire gauge than the NEC requirement to assure am-
ple current-carrying capability.
ple current-carrying capability.
• Never under size wire gauges.
Voltage Source
• Transformers block a large percentage of
Electro-Magnetic Interference (EMI). The Vilter
Vission 20/20 should be isolated with its own con-
trol transformer for the most reliable operation, see
Figure 2-1. Vission 20/20 with Individual Transformer.
Vission 20/20 should be isolated with its own con-
trol transformer for the most reliable operation, see
Figure 2-1. Vission 20/20 with Individual Transformer.
• Connecting the Vilter Vission 20/20 to breaker panels
and central control transformers exposes the Vission
20/20 to large amounts of EMI emitted from the
other devices connected to the secondary terminals
of the transformer. This practice should be avoided if
possible, see Figure 2-2. EMI and Vission 20/20.
20/20 to large amounts of EMI emitted from the
other devices connected to the secondary terminals
of the transformer. This practice should be avoided if
possible, see Figure 2-2. EMI and Vission 20/20.
Figure 2-1. Vission 20/20 with Individual Transformer
Figure 2-2. EMI and Vission 20/20