Toro 880S - Manual (Page 6)

SPRINKLER WILL (a) Constant 24 VAC from controller. (Electric Models)
NOT SHUT OFF – Check for voltage using a DVM. If voltage is present, disconnect wire.
If sprinkler closes, service controller. Refer to Controller Service Manual.
(b) Selector cam in manual "ON" position.
– Set to "AUTO" or "OFF" position.
(c) Debris in pilot valve assembly.
– Disassemble and remove all debris. (See Servicing Pilot Valve page 11.)
(d) Constant pressure from controller. (N.C. Models)
– Check pilot valve at controller for constant flow.
– Check elevation differential. Valve elevation should not exceed 0' above
controller elevation or 70' (21.3 m) below controller elevation.
Sprinkler Mechanism
PROBLEM POSSIBLE CAUSE – CORRECTIVE ACTION
SPRINKLER WON'T ROTATE (a) Debris wedged between stator and turbine.
– Remove obstruction.
(b) Drive assembly defective.
– Replace drive assembly.
(c) Nozzle base assembly defective.
– Replace nozzle base assembly.
HEAD STICKS UP (a) Dirt in riser assembly.
– Flush out. (See Flushing Procedure on page 11.)
(b) Damaged or missing return spring.
– Replace.
(c) Damaged riser.
– Replace.
POOR DISTRIBUTION PATTERN (a) Nozzle plugged with debris.
– Clean or replace nozzle.
(b) Nozzle orifice damaged.
– Replace nozzle.
(c) Low operating pressure.
– Determine why system overloaded and correct.
Main Valve
PROBLEM POSSIBLE CAUSE – CORRECTIVE ACTION
VALVE WON'T CLOSE (a) Continuous 24 VAC to sprinkler.
(Electric ) – Check controller for voltage source.
(b) Leak in pilot valve assembly.
– Replace pilot valve assembly.
(c) Plugged supply screen on piston.
– Clean or replace screen.
(d) Manual control selector on pilot valve assembly turned to "ON" position.
– Turn to "AUTO" position.
(e) Plunger movement restricted.
– Inspect and clean or replace.
(f) Valve cylinder misaligned with sprinkler body communication tube.
– Remove valve assembly and install correctly.
(g) Foreign object keeping valve from seating.
– Remove, clean and check valve for damage. Replace if necessary.
(h) Damaged piston seal or piston assembly.
– Replace valve assembly.
VALVE WON'T CLOSE (a) Leak in control tubing.
(Hydraulic) – Isolate and repair.
(b) Pilot valve leak in controller.
– Confirm by observing constant dripping from discharge line of controller.
Refer to Controller Service Manual.
(c) Valve cylinder misaligned with sprinkler body communication tube.
– Remove valve assembly and install correctly.
(d) Foreign object keeping valve from seating.
– Remove, clean and check valve for damage. Replace if necessary.
(e) Damaged piston seal or piston assembly.
– Replace valve assembly.
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