Honeywell Power Supply Circuit Board F50F Series Two 16x20

F50F - Determining Series One or Two

W8600F Series Two W8600E Series One	Choosing the replacement power box may be dependent on the series. If you do NOT have the optional wall mounted Remote Performance indicator (W8600F), the series does not matter. If you are replacing a power box of any series and do NOT have W8600, we recommend choosing the Series 2 Power box. F50F Series 1 was manufactured from 94 to 97. The series 2 was manufactured from 98 throught 06. The Series 1 power box comes with a 4 connector would be used for the optional W8600E. The Series 2 power box has a knock-out for a terminal strip. The terminal strip would be included with the optional W8600F. The F50F Series 2 power box is the same used in the current F300.
Power Box Series Two		Power Box Series One

Series One or Series Two

Use the Series One power supply if your current power box has the terminal strip for the W8600E. The terminal strip on power boxes made from 1994 to 1997 have pin connectors not compatible with the current power supply. Thus the Series One replacement power supply also includes the terminal strip and wire harness.

If you are replacing a power supply that has an existing W8600F, then order the Series Two power supply and reuse the existing terminal strip and harness. You also reuse the small daughter card that plugs in to the power supply. These items were originally supplied with the W8600F.

If your power box has a terminal strip with nothing connected because you are not using a W8600E or W8600F, then use the Series One power supply. Otherwise the Series Two does not have the terminal strip and the old terminal strip will be left to dangle.

The W8600F was introduced in 1998 and was originally available in white or taupe, but the taupe was discontinued mid 2006. The W8600F is now only available in white.

Though the W8600E was replaced by the W8600F in 1998, the W8600E was available as a replacement part until 2004. We no longer have any W8600E left.

Plug Versus Pin Connectors

The photo below shows the replacement power supply and a Series Two plug connection.
The photo below shows the same replacement power supply but a Series One pin connection. This Air Flow Sensor would be the type found in a Series One power box. Pin connectors are also used for connecting the neon lamp and terminal strip for the W8600E.
Only the Series One power supply includes instructions. The instructions show the wiring diagram for the Series One pin connections. The Series Two power supply does not include instructions because the plug connectors are simple.

Power Supply Inspection

First visually inspect the board. Most problems are visible such as a melted transformer winding or a burnt component such as the surge suppressors RV1 RV2.

Check the thin white ceramic resistor R3, the corner wire can break away. This can cause the collector plates to get power but not the ionizer wires.

Continuous cell sparking (for months) can burn out components or wiring. Resonant sparking causes elevated voltage swings that can break down the insulation on the high voltage wires. Check for scorching.

Often the fuse blows when the switching FET Q1 shorts, we believe from line spikes. Check the fuse continuity. A blown fuse typically reads 4.4M ohm because of circuitry in parallel.

The fuse is soldered in and not replaceable. If there is an internal short the fuse blows so to prevent any components from flaring up. Replacing a blown fuse will not fix the problem.

Honeywell does not release the circuit board schematics. Service tech's want to replace the complete board and be confident. Honeywell does not sell the discrete components. We do not do component level repair of the boards.

Replacing the complete board with a new one with a 2 year Honeywell warranty would be the most reliable repair.