Emerson 20/20 service manual Installation Recommendations, Proper Wiring Sizing, Voltage Source

Section 2 • Installation Recommendations

Proper Wiring Sizing

•Always size wire gauges as specified 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.

•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.

•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.

Figure 2-1. Vission 20/20 with Individual Transformer

Figure 2-2. EMI and Vission 20/20

Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.8.5153 2 – 1