Bridge Test - Graco ultra 750 Instruction Manual

Remove the bridge from the pressure control box and
perform this test to determine if the bridge is functional.
Refer to BRIDGE RECTIFIER REPLACEMENT , page
27. Use a continuity tester , such as multi–meter set on
the X1 ohms scale.
Perform all tests in the chart. If the bridge fails even one
test, it must be replaced.
Fig 23–1 shows the position of the wires on the bridge.
Using the chart at the right, connect the meter wires as
indicated by the black dots for each test, and then check
the continuity.
AC1 G1
AC2 G2
Fig 23–1
In Tests 1, 2 and 3, there should be NO continuity.
In Tests 4, 5 and 6, connect the + and – meter wires as
indicated, check continuity , then switch the meter wire
connections and check continuity again. You should get
NO continuity one way and YES continuity the other way.

BRIDGE TEST

–
+
In Tests 7 and 8, connect the meter wires as indicated by
the black dots. Touch the indicated "G" wire to one meter
wire, and then to the other. You should get NO continuity
one way and YES continuity the other way.
BRIDGE WIRES
G2 G1 –
CONTINUITY
NO
NO
NO
YES
NO
YES
NO
YES
NO
YES
OR
NO
YES
OR
NO
+ AC1 AC2
TEST 1
TEST 2
TEST 3
TEST 4
TEST 5
TEST 6
TEST 7
TEST 8
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