Vanguard Tri-Phase - Manual (Page 120)

TRI-PHASE OPERATING™ INSTRUCTIONS
24.0 Load Tap Change r
A built-in Load Tap Changer (LTC) controller provides the capability to raise or lower the LTC tap
position from the TRI-PHASE™ front panel. The LTC interface cable has four connectors that are
color coded. The two green cable connectors are labeled “RAISE”, and two white cable connectors
are labeled “LOWER”.
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LOWER fuse
250Vac/ 1A fast blow
dry contact switches
RAISE fuse
250Vac/ 1A fast blow
Figure 76.0 Load Tap Changer Controller
The components of the LTC that the operator needs to be aware of are:
• Two sets of dry contact switches
• Two 1A/250Vac fuses (5 X 20mm fast-acting type, 217 000 series P/N 217001)
• The RAISE switch electrically closes the raise contact
• The LOWER switch electrically closes the lower contact