Page 11 - Troubleshooting Paper Mill Hydraulics Sample Excerpt 2

No. 3 P.M. Winder Power Supply and Rider Roll

The RRX-SV solenoid is de-energized when necessary to raise and
lower the Rider Roll, which shifts the spool into the “B” (crossed
arrows) position. Oil is then ported through the “P” and “B” ports and
into the no. 15 relief valve. The oil at the no. 17 relief valve returns to
the tank through the “A” and “T” ports of the valve.

The solenoid has a manual override on the end of the housing. Prior
to actuating the override, make sure all personnel are clear of the
machine. If an AC coil is used in the solenoid, the resistance of the
coil can be checked to verify if it is good. A reading below 50 ohms but
not zero normally means that the coil is good. If infinity is read, the coil
wires are open. If zero resistance is indicated then the coil wires are
shorted out to each other. This valve is a normally open, two position,
four way, single solenoid, spring return, directional control.

No. 14 Directional Valve

15 Relief Valve

Oil is ported to this relief valve when the no. 14 directional valve
solenoid is de-energized. The valve should be adjusted to the
pressure required to lower the Rider Roll. If this valve were to fail
open, the pressure downstream of the no. 13 reducing relieving valve
will be very low.

Troubleshooting Papermill Hydraulics Page 41