Warner Electric Wheel-Brakes (Std) - Manual (Page 21)

21 Warner Electric • 800-825-9050 819-0514
Test the magnet for amperage capacity by using an
ammeter and a 6-volt battery (Figure 3-15). The
ammeter should indicate the amperage value given
on the magnet nameplate, plus or minus 10%. The
magnet amperage is rated at 70°F; therefore, a hot
magnet will indicate slightly lower and a cold magnet
will indicate slightly higher. If amperage reading is
incorrect, the magnet should be replaced, after first
making certain that the magnet leads are not defective
and that the magnet leads are making a good positive
connection with the magnet coil.
To test the magnet for a ground, connect an ammeter
and a 6-volt battery to the magnet (Figure 3-16). If any
amperage is indicated, a grounded condition exists.
The ground may be in either the leads or within the
magnet itself; therefore, check the leads thoroughly
before replacing magnet. Old style magnets having a
single magnet lead have one coil lead grounded to the
magnet shell; and therefore, will indicate proper
amperage when tested in this manner if not defective.
Figure 3-16
Testing Magnet for Ground
Replacing Magnet Leads
When magnet leads are found to be defective, they
can readily be replaced in the field. Refer to the repair
parts section for correct magnet lead to be used, or
order leads by magnet number and brake size.
Where magnet lead wires are soldered to the magnet
coil, it will be necessary to replace the complete
magnet lead assembly whenever one of the leads is
found to be defective. Pry up the two steel clips which
hold the magnet leads to the magnet shell, just enough
to slide wire out (Figure 3-17). Use a soldering iron to
melt solder on terminals and open copper clips holding
magnet coil leads.
Figure 3-17
Installing Magnet Lead Wires
Straighten coil leads. Remove the old magnet lead
assembly and replace with new. Bend steel clips tight
against the fiber insulator and magnet leads. Fit the
magnet coil leads into the copper clips, secure coil
leads in clips, and solder (Figure 3-18). Use caution in
soldering to prevent excess solder from grounding coil
leads to magnet shell.
If magnet lead wire is mechanically connected, pry up
steel clip holding lead to magnet shell, remove screw
fasteners, and remove defective lead. Clean magnet
coil lead and all contact surfaces.
Figure 3-18
Soldering Magnet Lead Wires
Copper Clips
Coil Leads
Steel Clips