Easy-Start ES Instruction Manual
Troubleshooting
SECTION 5
5-6
SCR Diagnostic Tests
SCR Service Procedures: (Hockey-Puk
Type)
When changing SCRÕs in the field, it is best to
remove the entire heat sink and lay it in a
horizontal position. However, if this is not
convenient, the following procedure can be used:
1. Remove the printed circuit logic board.
2. Remove the line power cable.
3. Remove the power strap between the two
short heat sinks.
4. Loosen the two bolts (or nuts) on the
pressure clamp until there is enough
clearance between the two heat sinks to
remove the SCR.
5. Remove the SCR.
6. Before installing the new SCR the old thermal
compound should be removed from the heat
sink and the mating surfaces should be
inspected for burrs or voids. If it is necessary,
use an extra fine grit emery cloth to smooth
the mating heatsink surfaces. Coat the
surfaces of the SCR with a thin coat of
thermal compound (Alcoa-2 or an equivalent
electrical joint compound). Wipe off the
excess compound.
Notice
-
Use sparingly - Apply only a thin
coat of compound.
7. Place the SCR against the side of the sink
that has the locating pin and make sure it
engages and is seated properly. Place the
other half of the heat sink against the SCR,
and holding the assembly together, tighten
the nuts on the compression clamp equally
until they are finger tight. Check that the
same number of threads are visible on both
clamp studs.
8. Tighten both nuts alternately in quarter-turn
increments until the correct pressure is
obtained. See Figures 5-1 and 5-2 for SCR
clamps.
SCR Mounting Clamp Pressure Can Be
Determined by the Pole Face Dimension
The Pole Face Is The Surface
Area in Contact With The Sink
Typical Dimension
Mounting
of SCR Pole Face
Pressure
Dimension ÒAÓ Inches
Lbs.
0.75" - 1.0"
1200
1.15" - 1.34"
2000
1.75" - 1.85"
5000
2.5" - 3.0"
10000
Easy ES-054
StockCheck.com
