User guide

TRI-PHASE OPERATING™ INSTRUCTIONS
24.0
Load Tap Changer
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”.
120
LOWER fuse
250Vac/ 1A fast blo
w
dr
y
contact switches
RAISE fuse
250Vac/ 1A fast blo
w
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