Zodiac - Contactor Z400 MD4/MD5/TD9 (18A) - R0815300

Zodiac – Contactor Z400 MD4/MD5/TD9 (18A) – R0815300

The Zodiac R0815300 is a genuine OEM replacement contactor designed for use within the Zodiac Z400 control panel range. A contactor is an electrically controlled switching device used to switch a power circuit on and off — in this context, it manages the high-current load of pool heating or filtration equipment connected to the Z400 system. This specific contactor is rated at 18A and is compatible with the MD4, MD5, and TD9 variants of the Zodiac Z400 pool controller, making it a targeted, model-specific spare part.

The Z400 is Zodiac’s professional-grade pool and spa control unit, widely used in residential and light-commercial swimming pool installations. When a contactor fails or shows signs of wear — such as failing to switch, chattering, or causing tripped circuits — replacing it with the correct genuine part ensures reliable operation of all downstream equipment managed by the controller. Using a genuine Zodiac contactor guarantees electrical compatibility, correct current rating, and physical fitment within the Z400 panel housing.

Technical characteristics and compatibility

This contactor carries an 18A current rating, which corresponds to the switching demand of pool equipment connected through the MD4, MD5, and TD9 model variants of the Z400 panel. The 18A rating is an important specification: it must match the load requirements of your system to ensure safe and reliable operation. Installing a contactor with an incorrect current rating — either too low or mismatched to the board — can result in premature failure or inadequate load handling.

As a genuine Zodiac spare part identified by SKU R0815300, this component is manufactured to the exact specification of the original part used in production. This ensures correct terminal sizing, coil voltage compatibility, and mechanical dimensions for a straightforward like-for-like replacement inside the Z400 control panel. Always cross-reference your specific Z400 model variant (MD4, MD5, or TD9) before ordering to confirm compatibility.

Suitability and application

This contactor is intended exclusively for use in Zodiac Z400 control panels of the MD4, MD5, and TD9 variants. It is a maintenance or repair component, suited for pool technicians, electricians, and experienced pool owners performing servicing on existing Zodiac Z400 installations. It is not a standalone product and must be installed within a compatible Z400 panel by a suitably qualified person. This part is appropriate for residential pools and light-commercial pool environments where the Z400 controller is the central management unit for pool equipment such as heat pumps, filtration pumps, or lighting circuits.