F4901 11a 24v Schematic Install Updated -
Fix: Measure the DC voltage across Terminal 86 and Terminal 85 while activating the trigger switch. If the meter reads 0V, check your control switch, control fuse, or PLC output programming. If it reads 24V, the relay coil may be internally damaged or open. Check resistance across 85 and 86 using an Ohmmeter; a reading of infinity indicates a dead coil.
SMD fuses and the surrounding components are highly sensitive to heat. Keeping your soldering iron on the pad for too long can lift the copper trace from the board or damage the fuse itself.
Use a multimeter in continuity mode to ensure there is no short circuit between VIN+ and VIN-, or VOUT+ and VOUT-. f4901 11a 24v schematic install
(Load) | +----o----+ | NO | | | +----o----+ COM Coil Terminals A1 (+) A2 (-)
[ +24V DC Trigger Signal ] | v +-----+ (Terminal 86) | | | [S] | <--- Flyback Diode (Anode to 85, Cathode to 86) | | +-----+ (Terminal 85) | v [ Ground / 0V ] ---------------------------------------------------------------------- [ High Current Power Source ] ---> (Terminal 30 / COM) | v / (Internal Switch Arm) / / | (Terminal 87a / NC) <----+----> (Terminal 87 / NO) | | v v [ Idle Load / LED ] [ Active Load / Motor ] | | v v [ Ground ] [ Ground ] Circuit Behavior Breakdown Fix: Measure the DC voltage across Terminal 86
Even experienced technicians make errors during an . Avoid these:
What (e.g., DC motors, LED arrays, PLC controllers) will it power? Check resistance across 85 and 86 using an
The request for "F4901 11A 24V" likely refers to the expansion board for the
[24 VAC Transformer] |____(Hot R)___________________________ [Thermostat R] | | | (Cooling/Heating Call W/Y) | | |_________________ v | [Actuator Terminal 2 / Switched Hot] |____(Neutral C)__|_____________________ [Actuator Terminal 3 / Neutral] | |_____________________ [Actuator Terminal 1 / Constant Hot] [Boiler/Pump Controller] |____(T1 T-Terminal)____________________ [Actuator End Switch Terminal A] |____(T2 T-Terminal)____________________ [Actuator End Switch Terminal B]
