Pt#121901 – CW‑H15 Float Switch Kit | Improves Water Level Detection (Lit 864584‑A)


⚠️ Safety Notice – Commercial Evaporative Cooling Products


This equipment must only be installed, commissioned, serviced and repaired by suitably qualified and licensed personnel.


Before commencing work, complete a task-specific risk assessment and ensure safe roof access, fall protection requirements, electrical isolation procedures, service clearances and appropriate PPE have been considered. All work must comply with applicable regulations, standards and manufacturer requirements.


Particular care must be taken when working at heights, in roof spaces, ceiling spaces and other restricted access areas. Additional consideration must be given to confined working conditions, electrical hazards, moving parts, water systems, wet surfaces, manual handling risks and weather conditions.


Do not proceed if safe access, weather conditions, required clearances, confined space risks or appropriate safety controls cannot be achieved and maintained.


Safety takes priority over diagnosis, repairs, installation schedules and customer expectations. If the task cannot be completed safely, it must not proceed until the risks have been adequately controlled.


Overview

Part Number: 121901
Description: Float Switch Kit CW-H15
Application: CW-H Commercial Coolers fitted with Multi‑Magic Water Manager controls
This article provides identification, use‑case guidance, compatibility, inclusions, installation summary, wiring details, and functional testing information for Pt#121901 – Float Switch Kit CW‑H15.

Purpose of the Kit

The CW‑H Float Switch Kit is a field‑installed accessory designed to provide reliable water level detection on CW‑H commercial coolers. The float switch operates in parallel with the 3‑pin water management probe and is used to improve robustness during low salinity operating conditions.
Key functionality:
  • Provides water level input during low salinity conditions (<100 µS/cm)
  • Mounted at the high probe position
  • Disables pump interlocks and related fault codes when configured correctly
  • CW‑H models only

When to Recommend This Kit

Recommend Pt#121901 – CW‑H15 Float Switch Kit in the following scenarios:
  • Sites consistently operating in low salinity conditions (<100 µS/cm) where probe‑based water sensing becomes unreliable
  • Repeated false “Reservoir Empty” indications despite adequate water level
  • Intermittent pump shutdowns or pump interlock events caused by unstable probe readings
  • Applications where incoming water quality or treatment chemistry affects probe accuracy
  • Customer complaints of inconsistent unit operation that temporarily resolves after a drain/refill cycle
  • As a reliability retrofit for CW‑H units after software is brought up to current production release
This kit is a reliability improvement, not a substitute for correcting water supply, filtration, or maintenance issues.

Related Symptoms & Operational Issues

The float switch kit may be relevant when diagnosing the following symptoms or fault conditions:
  • Reservoir Empty / Water Level Indication
– PLC or BMS indicates empty tank with water visibly present
  • Pump Interlock / Pump Protection Events
– Pumps disabled due to perceived low water level or unstable probe input
  • Low Salinity Related Lockouts
– Unit behaviour affected when salinity drops below probe detection threshold
  • Intermittent Unit Operation After Drain / Refill
– Temporary recovery after reset, pointing to unstable water level sensing


Note: When correctly installed and configured, the float switch provides a stable digital water level input and helps prevent recurring water‑level‑related nuisance faults on CW‑H units.


Compatibility Requirements

Before installation, confirm the cooler meets the following requirements:

Hardware

  • CW‑H commercial cooler
  • Multi‑Magic Water Manager control board P/N 671438

Software (Mandatory)

  • Water Manager software: 103R0425 or later
  • PLC software: 89R0525 or later
If software is not current, update before commissioning the float switch.

Kit Contents (Pt#121901)

Item

Part Number

Description

Qty

1

637694

Bracket – Float Switch CW‑H

1

2

865885

Sensor – Level Tank CW

1

3

804118

Cable Tie 292 × 4.8 mm Black

1

4

864584

CW‑H Float Switch Installation Instructions

1

Installation Summary

⚠️ Safety – Always isolate power before performing installation or wiring.
  1. Open the right‑hand access panel.
  2. Locate the 3‑pin water management probe.
  3. Assemble the float switch onto the supplied bracket.
  4. Mount the float switch bracket onto the existing probe bracket using the same fasteners.
  5. Ensure bracket slots align so the float height matches the probe height.
  6. Secure the cable and route toward the control box.
The top edge of the float switch bracket must align with the top edge of the probe bracket.

Wiring Information

  • Feed the float switch cable through the rubber gland below the control box.
  • Route up through the cord grips to the Multi‑Magic Water Manager PCBA.
  • Terminate into the 2‑way push‑in connector labelled “FLOAT”.
  • Polarity does not matter.
  • Secure all wiring with a cable tie.

Functional Test Procedure

⚠️ Important: Fully drain the reservoir before testing.
  1. Lift the float switch and hold for ≥ 5 seconds.
– PLC Monitor graphic should change from Empty → Full.
  1. Release the float switch.
  2. After 5 seconds, confirm graphic changes Full → Empty.
If graphics do not respond correctly, verify wiring and software versions.

Common Installation Issues

  • Incorrect software version → Float input ignored
  • Bracket misalignment → Incorrect trigger water level
  • Wiring not connected to FLOAT header
  • Water not fully drained during test