Thermal relay 2.5–4A – code: TELRD08 – HP Watermakers

Thermal relay 2.5–4A TELRD08 for HP Watermakers

The thermal relay 2.5–4A (item code TELRD08) is a protection component designed for use in the electrical panels of desalination units HP Watermakers. Its function is to contribute to the safety of the system by intervening in case of motor overload, helping to prevent overheating conditions due to abnormal currents.

This is a spare part identified by the code HP TELRD08, with commercial reference Schneider Electric (Telemecanique) TeSys LRD and correspondence LRD08. It is a typical choice in marine and plant applications where service continuity and motor protection are central aspects of maintenance.

Main features and details

Identifying data

• HP spare part code: TELRD08
• Manufacturer / Series: Schneider Electric (Telemecanique) / TeSys LRD
• Commercial reference: LRD08

Electrical and functional specifications (from provided data)

• Current adjustment range: 2.5 A – 4 A (calibration via front trimmer)
• Rated insulation voltage: up to 690V AC () at)
• Trip class: Class 10A
• Integrated auxiliary contacts: 1 NO (normally open) + 1 NC (normally closed)
• Reset type: selectable manual (red button) or automatic
• Mounting: direct plug-in under the respective thermal relay/contactor (e.g. series LC1D)

How it works in the electrical panel

In HP Watermakers systems the high-pressure pump requires constant operation; under certain operating conditions (e.g. worn mechanical components, circuit restrictions or supply line variations) the motor may increase current draw. In these cases the thermal relay helps protect by tripping when the current exceeds the set threshold.

Operating principle (functional description)

• Bimetal mechanism: the relay uses bimetallic elements carrying the motor current; when the set calibration is exceeded and after a time consistent with the trip class, the mechanism trips.
• Safety stop via NC contact: the trip acts on the auxiliary contact NC, interrupting the control circuit (typically the main contactor coil) and causing the protected load to shut down.

Typical applications on HP Watermakers systems

This thermal relay, thanks to its calibration range 2.5–4 A, it is indicated for electrical panels where the current per phase falls within this range. In the HP Watermakers context, it is reported as used on small and medium-sized desalters or on configurations where the current per phase is contained.

Indicated compatibility (from provided content)

• HP Automatic and Electronic Systems: specific versions of the series HP UC (Under Compact) and HP SC (Super Compact), including configurations with productions from 35, 50 o 70 liters/hour, depending on the panel setup and the installed motor.

Note: actual compatibility depends on the panel configuration (matched contactor, wiring, and calibration). In case of doubt, always verify the spare part code TELRD08 and the reference LRD08 directly on the installed component.

Advantages in maintenance and spare parts management

The TELRD08 is a component well suited for ordinary and extraordinary maintenance interventions, especially when correctly sized electrical protections need to be restored.

• Immediate identification: presence of HP code TELRD08 and commercial reference LRD08 for a quick comparison.
• Adjustable calibration: possibility to set the threshold in the field 2.5–4 A via front trimmer, useful to adapt the protection to the installed motor (within the range limits).
• Reset management: selection between reset manual o automatic based on the panel requirements and operating procedures.
• Integration into the panel: plug-in mounting under compatible contactor (e.g. LC1D), typical solution for compact and tidy panels.

Usage and operational notes

For correct use of the thermal relay, it is important to consider that the protection depends on the calibration and the insertion in the contactor control circuit. During replacement or adjustment, follow the plant manufacturer's procedures and good electrical maintenance practices.

Practical instructions (without replacing the manufacturer's instructions)

• Code verification: check that the replacement part indicates TELRD08 and/or the reference LRD08.
• Range check: make sure the required trip current falls within the range 2.5–4 A.
• Reset selection: set manual or automatic in accordance with the panel logic and onboard safety procedures.
• Mounting: plug-in installation under the designated contactor; check mechanical alignment and correct connection of auxiliary contacts NO/NC.

If the relay trips frequently, it is advisable to investigate possible upstream causes (hydraulic circuit conditions, pump status, any restrictions, power supply line conditions) before restoring operation.

FAQ – Frequently Asked Questions

What is the spare part code for this thermal relay?

The HP spare part code is TELRD08. The indicated commercial reference is Schneider/Telemecanique TeSys LRD: LRD08.

What is the current adjustment range?

The thermal relay is adjustable in the range 2.5 A – 4 A via front trimmer.

What auxiliary contacts are present?

There is 1 NO (normally open) contact and 1 NC (normally closed) contact integrated.

Is the reset manual or automatic?

The reset is selectable: manual (via red button) or automatic, depending on the setting chosen on the device.

On which HP Watermakers systems is it indicated?

It is reported as used on specific versions of the HP UC (Under Compact) and HP SC (Super Compact) series, in configurations where the required setting falls within the 2.5–4 A range. Verification of the installed component and the panel configuration is recommended.