BMS acceptance: what to check before signing the acceptance certificate

Start with a function matrix

Before testing, prepare a short table: condition, expected action, confirmation and pass criterion. For a transition to night mode, for example, define not only the fan stopping but also the state of valves, required protective functions and associated systems.

If a function is described as ‘the system operates automatically’, there is effectively nothing specific to accept. If the description states when it starts, which permissives it checks and how it responds to faults, the result becomes verifiable.

Check each point from its physical source to the screen

For an important sensor, check the location, unit, range, value at the controller input and BMS display. For an actuator, check the permitted command, feedback and physical response.

Check addressing separately. A plausible temperature from an adjacent zone can go unnoticed for a long time. Each point name must therefore be unambiguously linked to the equipment and room.

The BACnet Committee stresses the need to define in advance which information must be available when integrating different manufacturers’ equipment. Protocol support alone is not sufficient for functional acceptance. ²

Testing normal operation is only part of acceptance

Agreed transition tests are needed: start-up, shutdown, schedule changes, manual mode and return to automatic control. For a facility with standby capacity, verify that the standby unit receives a command and confirms readiness.

Scenarios for loss of a sensor, communications or power must be prepared separately. Critical systems require safe simulation, a test rig or an agreed maintenance window with standby provision. Mandatory protective functions or all cooling must not be disabled merely to demonstrate an algorithm.

We are interested not only in a ‘fault’ message, but in the state in which the equipment is left, and the procedure for returning to normal operation once the cause has been resolved.

A backup must be usable for restoration

A folder of screenshots is not a configuration backup. It will not restore the controller programme, connections, users or required settings.

In Metasys, for example, creating an archive backup and restoring it are separately defined operations. Restoration may be subject to database version restrictions and certificate requirements. ^{3 4}

We would therefore require a list of backup contents, the date, software versions and a description of the verified restoration procedure. Testing must not put the operating facility at risk.

What is handed over to the owner

The handover package should include up-to-date drawings, a points list, control sequence descriptions, setpoints, test records, backups, user accounts and operating instructions.

Licences, configuration access rights and the ability to have another contractor maintain the system must be agreed separately. This does not mean automatically obtaining the source code of a proprietary platform. It means defining, before procurement, a package of materials and rights sufficient for the owner’s needs.

Do not conceal seasonal limitations

If summer peak conditions cannot be tested in practice during winter, the test record must distinguish completed tests, simulations and deferred seasonal testing. An untested mode must not be marked as passed.

It is also useful to record outstanding defects, responsible parties and rectification deadlines. The acceptance certificate then does not become the point after which everyone forgets what still needs to be completed.

An accepted BMS is a system with verified functions, clear limitations and documentation that enables continued operation after the integrator’s work is complete.