Rivacold HT

What does Rivacold HT mean?

On the Carel µC SE process-chiller controller, Ht / HT is the high temperature warning: it is signalled when the temperature read by probe B1 exceeds the high-temperature alarm threshold set in parameter P16, with a delay so brief excursions don't trip it. The alarm table lists it as a temperature warning with automatic reset.

Symptoms

• Display shows Ht / HT
• The monitored temperature reads above the configured threshold
• Warning output/signalling active; cooling performance noticeably down

Common causes

• Heat load above the unit's capacity
• Condenser fouling, failed fan, or restricted airflow reducing capacity
• Refrigerant-side fault (undercharge, restriction) preventing the unit from holding temperature
• Threshold parameter (P16) set too close to the normal operating temperature

Diagnostic steps

1. 01

   Read the actual temperature

   Check the value the controller's probe reports against an independent measurement. If the reading is false, suspect the probe; if real, work the capacity cause.

2. 02

   Check the threshold parameter

   Confirm the high-temperature alarm threshold (parameter P16 on Carel µC SE) is set sensibly for the application before chasing a fault.

3. 03

   Check capacity basics

   Clean the condenser, confirm fans run, and verify the load on the unit hasn't increased beyond what it is sized for.

When to call a professional

If the threshold is sane, the probe reads true, and the condenser side is clean but the unit still cannot hold temperature, the refrigeration circuit needs diagnosis by a certified technician.