If the limits are normally closed during diagnostics, what should be checked if they are not functioning as expected?

When limits are normally closed and are not functioning as expected, checking for a malfunction in the safety switch is essential. Normally closed limits are designed to break the circuit and stop the operation of the HVAC equipment when they sense a condition that is outside of safe operating parameters, such as excessive temperature or pressure.

If the limits are not functioning properly, it is possible that the safety switch itself has failed or is stuck in a position that does not accurately reflect the true operational conditions. This could prevent the system from receiving the signals it needs to function safely, which is a crucial aspect of HVAC system operation.

Assessing the safety switch ensures that systems can maintain their protective measures. When the safety switch is compromised, it might either continuously allow operation when it should not or fail to allow operation when it is safe to do so. Identifying the integrity and functionality of the safety switch is, therefore, integral to diagnosing and troubleshooting issues related to the HVAC system’s limits.