How to fix a Scully ST-15C Monitor with no lights on?
If the Scully Monitor has no lights on, it could be due to several reasons: * There's no power to the control unit. Check the power supply connection. * The bulb is blown (on older units with incandescent lamps). Replace the bulb. * The input power fuse (F1) is blown. Replace the blown fuse. * The control module is defective. Replace the control module.
What to do if the red light stays on the Scully ST-15C?
If the red (Non-permissive) light stays ON when connected to a vehicle with a Scully thermistor sensor or 2-wire optic sensor (or Scully tester) AND/OR the LED on the Control Module (circuit board) is not flashing ON-OFF, consider the following: * There may be a fault in the wiring to the junction box and/or plug. Inspect and repair the wiring. * The sensor might be wet or faulty. Replace the sensor. * There could be a fault in the wiring on the vehicle. Inspect and repair the vehicle wiring. * The plug to socket connection may be bad. Check and secure the connections. * The Control Module may be defective. Replace the Control Module.
Why isn't my valve/pump activating when the green light is on the Scully Monitor?
If the green (Permissive) light is ON, but the control contact output does not activate the valve/pump, it could be due to: * A blown Control Output fuse (F2). Replace the blown fuse. * A wiring defect in the control output contact wiring. Inspect and repair the wiring. * A defective Control Module. Replace the Control Module.
Explains the ST-15C's function as a single point overfill prevention monitor and its sensor compatibility.
Details model suffixes (E, L, K) indicating Explosion-proof enclosure, Indicator Lights, and Key Lockable Bypass Switch.
Describes the explosion-proof enclosure ('E' suffix) suitable for hazardous locations and conduit entry requirements.
Explains the meaning of the red and green indicator lights on the controller enclosure.
Details the function of the lockable bypass switch ('K' suffix) for emergency operation.
Describes the LED on the control module indicating Dynamic Self-checking (Dynacheck) operation.
Details the volt-free, normally open output contact rated at 250VAC, 5A for controlling valves or pumps.
Lists the two user-replaceable fuses: a 1-Ampere main fuse (F1) and a 5-Ampere control fuse (F2).
Provides key technical data including temperature range, power requirements, sensor types, and enclosure ratings.
Mentions the necessity of plug and cable assemblies for inter-connection to vehicles.
Details the SC-8B Sculcon Junction Box with 8B Green Plug & Cable for vehicle connection.
Covers selecting a mounting location, vertical mounting, and precautions for conduit entry and sealing.
Directs users to wiring diagrams and emphasizes compliance with regulations for electrical installation.
Details routing mains power wires through the top left-hand entry and connecting to the terminal block.
Explains connecting a wire from the enclosure-bonding stud to the earthed metallic structure of the gantry.
Describes routing control output wiring and connecting to output contact terminals on the terminal strip.
Details connecting intrinsically safe signals from the ST-15C to the Sculcon Plug & Cable Unit via the bottom entry hole.
Outlines the steps for performing initial system checkout and verification.
Suggests using the Scully Model ST-2-CBE Series Tester for commissioning tests.
Provides instructions for applying power, checking lights, and testing permissive/non-permissive states.
Explains how the ST-15C controller behaves during loading and in case of faults or liquid level detection.
Recommends annual inspection of the enclosure for corrosion and replacement of the inhibitor capsule.
Discusses the corrosion inhibitor capsule, its lifespan, and recommended replacement of the cover O-ring.
States that the internal circuitry is non-repairable and requires module replacement.
Provides step-by-step instructions for removing and installing a replacement control module.
Explains that LED indicator lights require no maintenance and should be replaced if faulty.
Describes how to replace the bypass switch box or the switch itself if faulty.
Offers recommendations for maintaining the Sculcon Junction Box and cable unit, especially in corrosive environments.
Provides a guide for diagnosing and resolving common problems encountered with the ST-15C.
Presents dimensional drawings (DWG 31412) of the ST-15C control unit enclosure.
Provides dimensional drawings (DWG 63039) for the Sculcon Junction Box.
Illustrates (DWG 61442) the typical mounting configuration of the control unit and junction box.
Shows the wiring connections (DWG 61575) required for installing the ST-15C system.
Depicts a typical loading rack control circuit (DWG 61441) showing permissive contacts.
Details the internal wiring (DWG 31392) for the ST-15C EL model.
Details the internal wiring (DWG 31393) for the ST-15C ELK model.
Lists 120VAC CENELEC models and their corresponding replacement parts.
Lists 240VAC CENELEC models and their corresponding replacement parts.
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