TRNSYS 15 Troubleshooting

1. Check the List File for Errors
   • Ignore ‘warnings’ and focus on ‘errors’.
   • The error might not be on the last line of the .out file. Look for ERROR messages near the end of the list file (***.lst).
2. Reduce Timestep
   • Try reducing the timestep from 0.02 to 0.01 or 0.005.
   • This can resolve issues like MATH SQRT-1, floating-point errors, or convergence problems.
3. Verify Filepath
   • The filepath should not contain any problematic characters, spaces, or be excessively long.
4. Energy Balance Issue at 7% Simulation
   • If the error occurs at 7% simulation, the energy balance has failed.
   • Check the list file to verify it is an energy balance issue.
   • Verify parameters for correctness, including units (e.g., L vs m3 for volume, mm vs m for length).
   • Use Kdiff3 against a working deck to identify parameter value anomalies.
5. Use Kdiff3 for Deck Comparison
   • Utilize Kdiff3 to compare against a similar working deck file.
   • Identify differences and revert parameters back to a working deck one at a time until the issue is identified.
6. Turn On the Plotter
   • Enable the plotter to watch the simulation - change parameter 9 of the Type 65 plotter to 1 to turn on the plotter.
   • Look for rapidly changing variables or values outside realistic ranges.
   • Add extra variables to the plotter if necessary.
7. Errors relating to include file
   • Issues related to reading weather files or equations involving Tamb “variable not specified.”
   • Ensure all include files and weather files are set to “Ready only.”
   • Check weather files in C:\TRNSYS15\Include&weather\ for 0kb size, indicating the file does not exist; copy it from the source folder.
   • Confirm that include files have full filepath references to weather files (e.g., C:\TRNSYS15\Include&weather\canberra.tmy).
8. Units not converged: simulation may not converge for several reasons, but overall the simulation cannot find a solution to all the implicit equations. Maybe the timestep is too large, or insufficient thermal capacitance in a closed fluid loop, or control states are switching rapidly.

• Reduce the time step - 0.02, 0.01, 0.005, until convergence is reached.
• Add pipes to the system. Increase pipe size and reduce heat loss to achieve equivalent heat loss but with extra fluid volume in the system. Each pipe must have sufficient volume so that the flow through the pipe does not exceed the pipe volume in a single timestep. Perform some calculations on pipe volume and flow rate at the current time step to evaluate what time step or pipe volume is required to avoid this error.
• If many components, check the component order in the simulation so that components are in a logical order in the direction of flow around the system. Define control strategies first, then components, then plotters at the end.
• Replace GT(A,B) equations with Type 2 controllers. Adding hysteresis to the simulation slows down rapid switching between control states.

9. Files keep reverting to Read-Only

• Investigate issues related to syncing from Sharepoint.
• Confirm that Microsoft Office is installed from the EnergyAE license.
• Request a .zip copy of the Templates folder sent via email.

10. Check Text File Encoding

• Ensure the text encoding of the text file is correct; UTF-8-BOM can cause issues, so change to UTF-8 or ANSI.
• In Notepad++, open the deck file, change Encoding -> UTF-8.

<figure><img src="/kms/image (41).png" alt="" width="563"><figcaption></figcaption></figure>