NEXUS Spa Heater
Cable – Optional Control for Spa Internal Heater
The Auxiliary Heater Cable is an optional connection that
allows the Nexus Evo 6 and Evo 7 EVI heat pumps to control the internal
electric heater of a hot tub (up to 3kW). Designed to act as a relay or switch live, it does not supply power
directly but enables intelligent activation of the spa heater based on logic
settings within the heat pump.
The cable is 5 metres long,
providing ample length for most standard installations between the heat pump
and spa control system.
Key Features
Three Modes of Operation
The cable provides intelligent control through three
activation methods:
Manual
Control
The internal heater can be
manually switched on or off by holding the temperature up button on the heat
pump for three seconds. This provides a simple manual override or test
function.
Ambient
Temperature Trigger
An adjustable parameter allows the
installer to set a minimum ambient air temperature. If the temperature drops
below this point, the heat pump will trigger the spa’s electric heater to
support water heating.
Temperature
Difference Trigger
Another parameter monitors the
difference between the current water temperature and the desired set point. If
this gap is between 1°C and 10°C, the internal heater is automatically
activated to assist the heat pump in reaching the target temperature more
quickly.
Installation Details
The Auxiliary Heater Cable must be connected to only one side
of the spa heater terminal. The other side of the heater remains connected to
the spa’s live output. As this cable acts as a switch live and not a power
source, both terminals of the heater should never be connected to the heat
pump.
This setup ensures the internal heater is safely and reliably
controlled without interfering with the spa’s existing wiring or systems.
Supplied Installation Kit
Each cable includes a 5mm bolt, nut,
washer, spring washer, and heat shrink, allowing a secure,
professional connection without cutting or modifying
any OEM wiring. This makes the installation fully reversible and
ideal for both new and retrofit applications.
Compatibility
- Nexus
Evo 6
- Nexus
Evo 7 EVI
Specifications
- Cable
length: 5 metres
- Max
supported heater load: 3kW
- Relay/switch
live control (does not supply power)
- Fully
reversible, OEM-safe installation
