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Mow Circuit Cutting Deck Blade Braking
When the operator turns the PTO switch OFF or if a deck is raised with the PTO switch ON, deck control manifold solenoid valve (S) is
The inertia of the rotating cutting blades, however, effec- tively turns the deck motor into a pump causing an in- crease in pressure as the flow from the motor comes up against the closed logic cartridge (LC2). When this pres- sure builds to approximately 600 PSI (41 bar), relief valve (RV2) opens which allows a small amount of hy- draulic flow to return to tank through a manifold sensing line (Fig. 11). This flow causes a pressure increase that shifts logic cartridge LC2 to once again allow oil flow from the motor (Fig. 12). When motor return pressure drops below 600 PSI (41 bar), relief valve (RV2) reseats and causes LC2 to close again blocking return flow from the deck motor to further slow the cutting blades. This action of the brake relief valve opening and the logic car- tridge shifting occurs several times in a very short time frame as the blades finally come to a stop. Once the blades have stopped, logic cartridge LC2 remains in the neutral position to keep the deck motor from rotating.
| DECK MANIFOLD |
| G |
M1 | RV2 | RV1 | P1 |
DECK |
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| LC1 |
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MOTOR |
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| S |
M2 | LC2 |
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| P2 |
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| CD |
Figure 10
| DECK MANIFOLD |
| G |
M1 | RV2 | RV1 | P1 |
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| LC1 |
DECK |
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MOTOR |
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| S |
M2 | LC2 |
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| P2 |
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| CD |
Figure 11
| DECK MANIFOLD |
| G |
M1 | RV2 | RV1 | P1 |
DECK |
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| LC1 |
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MOTOR |
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| S |
M2 | LC2 |
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| P2 |
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| CD |
Figure 12
Hydraulic System | Page 4 | Groundsmaster |