Vanguard ATRT-03_03B S2 - Manual (Page 19)

REV 2 ATRT-03 S2, ATRT-03A S2, AND ATRT-03B S2 USER’S MANUAL
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2.5 Replacing the Load Tap Changer Controller Fuses
The ATRT-03 S2 features a built-in Load Tap Changer (LTC) controller that can raise or lower the
LTC tap position from the front panel. The LTC controller circuit uses two 250 Vac/2A, NO, relay
contacts to simulate the LTC Raise/Lower switches. Each relay contact is protected by a 1A/250
Vac fuse (5 X 20mm, fast acting). The fuse should be replaced with a Littlefuse P/N 217001 or
equivalent. Follow the instructions below to replace the LTC controller fuses:
a. Remove the ATRT-03 S2 from its casing by removing the four screws from the bottom of
the case: