Carrier 30XW Fault Code 31

31
Loss of communication with SCPM B1
Warning
SAFETY WARNING: Commercial chillers contain high-pressure refrigerants and high-voltage electrical components (208V-4160V). Only EPA Section 608 certified technicians should perform diagnostic work. Always follow lockout/tagout procedures and wear appropriate PPE. Do not attempt repairs without proper training and equipment.
AI Summary

Carrier 30XW Fault Code 31 is a warning alarm indicating: Loss of communication with SCPM B1. The most common causes include CCN cable to circuit B damaged. Estimated repair time: 30-90 minutes (requires network diagnostics and cable/connector inspection). This alarm requires immediate attention by a certified HVAC technician.

Alarm Description

Loss of communication with SCPM B1

Brand: Carrier  |  Model: 30XW (Water-Cooled Screw Chiller (AquaForce))  |  Code: 31  |  Severity: Warning

Observable Symptoms

  • Controller display shows communication error or blank screen
  • BAS/EMS system shows chiller as offline or in alarm state

What to Check First

Before diving into detailed diagnostics, start with this quick first check:

Quick Start: Check CCN cable

Probable Causes

  • CCN cable to circuit B damaged
  • SCPM B1 power failure
  • Address conflict

Recommended Inspection Steps

  1. Check CCN cable
  2. Verify 24VAC supply
  3. Check addresses
  4. Replace SCPM B1

Required Tools & Equipment

  • Safety PPE (gloves, safety glasses, face shield)
  • Wire tracing and continuity tester

Estimated Repair Time

30-90 minutes (requires network diagnostics and cable/connector inspection)

When to Call a Professional

  • If the fault persists after completing all recommended inspection steps
  • If you observe unusual noises, vibrations, or oil leaks from the compressor
  • If refrigerant charge levels are outside OEM specifications and EPA-certified recovery is needed
  • If electrical measurements show voltage imbalance greater than 2% between phases
  • If the fault recurs immediately after reset, indicating an unresolved safety condition
  • Contact an authorized Carrier service representative for warranty-covered repairs

Related Fault Codes

Other Carrier 30XW codes that may be related:

123714

OEM Service Manual Reference

OEM Reference: Carrier 30XW (AquaForce) Installation, Operation and Maintenance Manual. Available through Carrier Commercial Systems.

Frequently Asked Questions

What does Carrier 30XW fault code 31 mean?

Fault code 31 on a Carrier 30XW chiller indicates: Loss of communication with SCPM B1. This is a warning alarm that requires diagnostic attention.

What causes Carrier 30XW alarm code 31?

Common causes include: CCN cable to circuit B damaged; SCPM B1 power failure; Address conflict

How do I fix Carrier 30XW error code 31?

Follow the recommended inspection steps below. Start with the quick check, then proceed through each step. If the fault persists after all steps, contact an authorized Carrier service representative.

Disclaimer: All lookup data is for reference only. Do not use this information to replace certified professional HVAC technician judgment. Always refer to original OEM official service manual for Carrier 30XW service procedures.