SC Max Chlorinator (Last Sold 2020) exploded view & spare parts

Davey SC Max Chlorinator exploded view & spare parts

This page covers the complete exploded-view diagram and numbered bill of materials for the Davey SC Max Chlorinator, sold under the factory references ESC MAX and ESC MAX PLUS. The ESC Max was Davey’s solution for large residential pools as well as smaller public and commercial installations, with high-output models suited to resort pools, public pools, and swim schools. The diagram spans both the 77 g/h and 155 g/h output variants of the unit, covering the power supply enclosure, the cooling assembly, and the salt-electrolysis cell and plumbing connections. Although this model was last sold in 2020, genuine spare parts remain available for ongoing servicing and repair, and you should be able to identify the part you need within a few minutes using the diagram and list below.

How to use the numbered diagram to find your part

Every numbered call-out on the diagram corresponds directly to a row in the parts list on this page — locate the area of the unit that concerns you, note the position number printed on the diagram, and then match it to the same number in the list to reveal the description and SKU. Once you have the SKU, add it straight to your basket. Be aware that several position numbers appear more than once in the list: positions 3, 4, 12, and 14 each have two variants — one for the 77 g/h model and one for the 155 g/h model — so you must confirm your unit’s output rating before ordering. Check the label on your SC Max cabinet; it will state either “77” or “155” (referring to the chlorine output in grams per hour). Where a position number carries lettered suffixes on a diagram — for example “6a / 6b” — those letters typically indicate a size or material difference rather than an alternative fit, so treat each lettered suffix as a distinct part. Always cross-reference the written description in the parts list against what you see on the unit to catch any discrepancy before you order.

Main replaceable assemblies on the SC Max Chlorinator

The SC Max is broadly divided into three serviceable zones: the electrical enclosure, the cooling assembly, and the cell-and-plumbing assembly. Inside the enclosure, position 1 (Fuse Holder, SKU M2950) and position 2 (E Switch, SKU M2004) are the first components to check when the unit fails to power on or trips unexpectedly. The control board at position 3 (PCB SC MAX — SKU M1125-77ORPSP for the 77 g/h unit, M1125-155ORPSP for the 155 g/h unit) governs output regulation and ORP sensing, and the transformer at position 4 (M1734 for 77 g/h, M1735 for 155 g/h) supplies the low-voltage DC current to the cell. The cable entry point at position 5 (Strain Relief / H-4404 Cable Gland, SKU M4514) is worth inspecting whenever there are signs of moisture ingress into the cabinet. The cooling stack — comprising the plastic fan guard (position 6, SKU M4504A), the heat sink (position 7, SKU M4512M), the fan gasket (position 8, SKU M1626A), the 120 mm metal fan guard (position 9, SKU M4504B), and the fan bracket (position 10, SKU M1626) — keeps the power electronics within safe operating temperatures and should be checked for debris or cracked components during routine servicing. The gas sensor at position 11 is supplied as a complete Gas Sensor Service Kit (SKU 32746), which is the correct way to replace this safety-critical item. The self-cleaning reverse-polarity cell at position 12 (SKU M4922SP for 77 g/h, M4923SP for 155 g/h) is the heart of the chlorination process and the most commonly replaced component. Finally, the plumbing connection to the pipework is made up of the union O-ring (position 13, SKU M1573), the union tail (position 14) and the union nut (position 15, SKU M1571), which together form a watertight union that can be dismantled for cell removal without cutting the pipework.

Choosing between variants and pack sizes

Four positions in this BOM require you to choose between two variants before ordering. For positions 3 and 4 (PCB and Transformer) and position 12 (Cell), the split is purely by output rating: 77 g/h or 155 g/h. Fitting the wrong-rated PCB or transformer can result in the unit running outside its designed parameters, so confirm your model’s output from the cabinet label before purchasing. At position 14, you have a choice between the standard 80 mm Union Tail (SKU M1572) and the 80 mm-to-50 mm Reducing Union Tail (SKU M1576); the reducing tail is only appropriate where the existing pipework downstream of the cell is 50 mm rather than the standard 80 mm, so measure your pipe before ordering. When replacing the electrolysis cell, ensure you use the correct genuine replacement cell to match your system — an incorrect cell diameter will not seal correctly against the union O-ring at position 13 and may result in leaks or reduced chlorine output.