Guardian 4389 Repair Manual page 72

SECTION 3.4
DIAGNOSTIC TESTS
8. Connect one test lead to TX Terminal 1. Connect the
other test lead to the transformer case. INFINITY
should be measured.
9. Connect one test lead to TX Terminal 7. Connect the
other test lead to the transformer case. INFINITY
should be measured.
10.Connect one test lead to TX Terminal 9. Connect the
other test lead to the transformer case. INFINITY
should be measured.
11.Connect one test lead to TX Terminal 1. Connect the
other test lead to TX Terminal 10. INFINITY should be
measured.
12.Connect one test lead to TX Terminal 1. Connect the
other test lead to TX Terminal 7. INFINITY should be
measured.
13.Connect one test lead to TX Terminal 10. Connect the
other test lead to TX Terminal 7. INFINITY should be
measured.
Page 70
PART 3
RESULTS:
For Steps 5, 6, and 7, replace transformer if an open
is indicated, or if the resistance value indicated is
zero. If the resistance value is not within the approxi-
mate range, proceed to test 65.
For Steps 8 through 13, replace the transformer if it
fails any of these steps.
Figure 6. Transformer (TX)
"V-TYPE" PREPACKAGED
TRANSFER SWITCHES
225A
224A
N2
225
224
N1