NA7.13 Compressed Air System Acceptance

Use Form NRCA-PRC-01-A

Purpose of the Test

The purpose of functionally testing the controls of a compressed air system is to confirm that the controls are set up in a compliant manner.  A compliant system will choose the most efficient combination of compressors, given the current air demand as measured by a sensor, according to Standards Section 120.6(e)2. This test is designed for flexibility, as this covers both newer compressed air systems designed for use with controls and older compressed air systems under direction of controls for the first time.

Instrumentation

Instrumentation to perform the test includes:

•      Power meter(s) for each compressor

•      Pressure transducer(s) for each compressor

•      Sensor or set of sensors to measure or infer current air demand, including but not limited to:

o  Flow meter

o  Set of pressure transducers

o  Pressure transducers and power meters

Test Conditions

Equipment installation is complete (including compressors, storage, controls, and piping).

Compressed air system must be ready for system operation, including completion of all start-up procedures per manufacturer’s recommendations.

For a new compressed air system, the trim compressor(s) must be identified prior to conducting the test.

Document the initial conditions before overrides or manipulation of the settings, if any. All systems must be returned to normal at the end of the test.

If using a valve to achieve a steady demand, ensure that this will not affect any equipment downstream.

Estimated Time to Complete

Construction Inspection: 1 to 1.5 hours (depending on complexity of the system)

Functional Testing: 1 to 3 hours (depending on familiarity with the controls and issues that arise during testing)

Acceptance Criteria

The states of each compressor will be observed throughout the duration of the test.  By the end of the 10-minute duration, each compressor must not exhibit short-cycling or blow off.

For new compressed air systems, the trim compressors are the only compressors that can be partially loaded.  All base compressors must be either fully loaded or off by the end of the test.

Potential Issues and Cautions

For older systems, it may not be feasible to run at a steady demand for 10 minutes.  In these cases, still observe the compressors to ensure that the controls are operating efficiently.