Testing & Commissioning Example

Part 1 - Description of the works Testing and commissioning

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Testing and commissioning General Overview

Each M&E contractor will be responsible for the testing and commissioning of their stand-

alone installations. In some instances one contractor’s commencement will be dependant

upon another’s completion or partial completion. For instance: -

• All commissioning is going to be dependant upon the provision of the LV

electrical power supplies. Temporary supplies can be provided to a certain

extent, which should be viewed as a last resort.

• The final commissioning of chillers and cooling towers is going to be dependant

upon the chilled water flushing.

• BMS commissioning is partially dependant upon the commissioning of the

systems with which it interfaces.

• Fire alarm commissioning is partially dependant upon the commissioning of the

systems with which it interfaces.

Incomplete building construction and finishes works can add to commissioning delays: -

• Escape staircases cannot be pressure tested if there are walls and doors

missing.

• Busbars cannot be energised whilst contractors are still using them as part of

their scaffolding arrangements.

• Generator engines cannot be started up whilst bricklayers are making good

around the flue discharges.

• Final decorations and finishes should be complete where final fix items have to

be installed.

It is not the responsibility of the M&E contractors to point out the missing construction

items that are likely to affect their commissioning.

Due to their failings particular M&E contractors may not be able to meet the programmed

commissioning date. So they are hardly likely to present a list of construction items that

will delay the commencement of their commissioning in sufficient time for those items to

be cleared before a commencement date they know they cannot meet. It is more than

likely that they will drip-feed the reasons why they can’t start as a smoke screen for their

own failings.

So it is important that meetings are held well in advance of the commissioning

commencement date to establish the following: -


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• The power on requirements associated with commissioning.

• The progress of design matters, particularly regarding software writing.

• Are all of the control panels available?

• Are all of the controls available?

• Are all of the interfaces clearly established?

• Are the commissioning resources bought at the award stage still available.

• Are all commissioning method statements in place.

• There are no misunderstandings regarding responsibilities i.e. who provides the

means of high level access.

• Any items of outstanding builderswork that could effect commissioning.

Throughout the commissioning period the majority of the work is going to have to be

demonstrated to the consultants and the local authority’s satisfaction. This can lead to

problems regarding attendance when one particular body cancels for some reason. It is

important to ensure that this attendance time has been purchased from the contractors.

It is important to ensure that the commissioning periods of all individual M&E trades tie-in

to the same dates. However, the overall commissioning period for the electrical

contractor will need to commence before the dates indicated in the other trades contract

programmes. This is because they need to commission their own MV and LV supplies

prior to the LV supplies being available for other trades commissioning.

The commissioning power availability dates for each of the main areas need to be

separately identified on the contract programmes.

It is important to show the commissioning periods as separate items. For instance Figure

1.7 clearly indicates that the “Overall commissioning period” is complete by the end of

week 45, and the “Integrated System Testing” commences on week 46.

Figure 1.7 Typical Contract Programme Commissioning Sequence


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Don’t wait until PC for the Operating Manuals (O&M’S), draft copies should be available

well in advance.

Integrated System Testing (IST) When the contractors have completed their stand-alone commissioning and the

associated interfaces with other trades i.e. the fire alarm and in particular the BMS. They

will all to some extent (perhaps only in attendance) partake in the Integrated System

Testing (IST). This is where all of the stand-alone commissioned systems work together

to perform the functions as defined in the specifications. This will include: -

• Automatic sequential re-starting of systems by the generator following a power

failure.

• Functionality of all plant in conjunction with the BMS in fully automatic operation.

• Functionality of all plant in conjunction with the fire alarm in fully automatic

operation.

In order for this to work correctly all installation and commissioning works associated with

the IST need to be complete before its commencement.

It will be said that the IST can be carried out in one-week, which in theory may be correct;

in practice it is best to allow four-weeks.

Black Building Testing At sometime during the IST period the Black Building Tests need to be carried out.

These can be done either at the beginning or end of the IST period. The timing is usually

determined by how well or not so well the IST is performing.

The Black Building Tests basically relate to the operation of the electrical changeovers in

respect of partial and total power failure scenarios.

It will be said that the Black Building Tests can be carried out in two-days, which in theory

may be correct; in practice it is best to allow two-weeks.

Individual services testing and commissioning

Ventilation The ventilation ductwork testing will be carried out and witnessed by the consultants

during the natural progression of the installation works. The testing of ductwork involves

air pressurisation for a given period of time. Following the successful testing particular

aspects of the ductwork installations regarding supply air require insulating; insulating is

also referred to as “lagging”. The insulation of ductwork should not be carried out until

the ductwork has been tested.


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There are occasions where parts of an installation may require sectional testing before

they are fully complete in order to allow for the commencement of a following trades work.

For instance, sectional testing would be necessary for ductwork that was going to be

concealed within riser shafts, if it meant that the riser encasement was critical for another

facet of the project’s commencement. Sectional testing would also be necessary for all

M&E services installed above a none-accessible ceiling in a lobby or reception area, if the

ceilings had to commence before the M&E services were entirely complete.

The commissioning of a ventilation system should not commence until it has been

thoroughly inspected. The AHU’s, ductwork, plenums and attenuators need to be cleared

of debris and dust.

The commissioning of individual ventilation systems involves: -

1. Power on and live cable testing.

2. Ensuring that the fans and controls operate correctly when turned on.

3. Ensuring that the BMS control is operational.

4. The total volumes of air movement are in accordance with the specification.

5. The balancing of the air around the system.

6. The fans and controls operate in smoke extract mode with the fire alarm.

Not all ventilation systems will have the full extent of the above six items associated with

their commissioning. Some ventilation systems work in conjunction with one-another and

could be partially complete for a period of time. It is unlikely that any of the ventilation

systems would be commissioned with the BMS in “automatic” prior to the IST.

Mechanical

Mechanical pipework testing The mechanical pipework testing will be carried out and witnessed by the consultants

following sectional completions of the installation. The testing of pipework involves water

pressurisation for a given period of time. Following the successful testing particular

aspects of the pipework installations require insulating. The insulation of pipework should

not be carried out until the pipework has been tested. There are instances where the

pipework will have to be trace heated prior to being lagged.

Similarly to the ventilation there are going to be instances where sectional testing of

pipework is required. The chilled water pipework cannot be tested until it is filled with

water, and it should not be filled with water until the entire pipework installation, or large

sections of it have been completed.

Once the chilled water system pipework has been filled and is undergoing pressure

testing, all of the leaking welds and flanged joints should reveal themselves.


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When the leaks have been discovered and rectified the system can be re-filled and re-

tested. (The system may have to be fully drained in order to carry out the repairs).

The capability of the mechanical contractor will determine how many times they have to

drain and re-fill the system to repair any leaks.

Chilled / condenser water pipework commissioning The items described below refer also to the commissioning of the condenser water

pipework.

The chilled water pipework system is fundamental to the final commissioning of all

ventilation systems that require cooling. Therefore any delays to the chilled water

pipework installation and its subsequent commissioning will extend the IST period and

delay the project completion date.

With regard to its commissioning the chilled water pipework system as an entity is

probably one of the most difficult to accomplish. Because as stated within the Mechanical

– Description of Works “The chilled water pipework extends throughout almost every area

of the building” This will include the key areas of the project i.e. basement level plant

rooms, risers and levels 17 and 18 plant rooms.

Once the pipework has been fully tested to the approval of the consultants and the

commissioning manager then the flushing process can commence.

Flushing involves the pumping of chemically treated water around the pipework. In doing

so

this treatment removes all of the burrs and debris within the pipework that were created

during the welding process. The flushing process will be repeated until the entire residue

has been removed from the pipework to the satisfaction of the commissioning manager.

A complete description of the chilled water commissioning process is detailed in template

TP01 – Chilled Water Plant Room.

The pipework installation is the only part of the chilled water system that gets flushed.

The plant items i.e. chillers, AHU’s, pumps & fan coil units remain isolated from the

system and by-pass valves and spades are inserted ensure that the water flow is

maintained throughout the pipework.

This means that the residue does not enter into and clog up the small bore pipework that

makes up the internal cooling coils of the plant.

Once all of the debris has been flushed out of the pipework the by-pass valves are closed

and clean treated water is allowed to flow through all of the coils within the plant.


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The above describes the correct method of carrying out the work. Of course in the real

world all manner of shortcuts are utilised to meet the commissioning date.

These usually involve the blanking off of pipes in risers that should serve areas where the

pipework has not been installed (for whatever reason) prior to the commissioning

commencement date. But being eager not to delay the programmed flushing

commencement, mechanical contractors have been known to commence the flushing on

a partly completed pipework installation.

Then following its installation the missing pipework is back-flushed using the clean treated

water that is flowing around the system. The effects of this can be quite catastrophic,

depending upon how much of the systems pipework has been back-flushed, and how

much of the residue is blocking the coils of the plant.

Unfortunately this may not be known until particular plant items fail to accomplish their

specified criteria. Then it becomes a case of stripping down each particular plant item

and manually cleaning out the coils.

It has been known for a manufacturer to spend six-weeks cleaning out their chiller coils

as a result of back-flushing incomplete pipework.

Other items to be aware of during the chilled water commissioning process are: -

• Faulty main valves blowing causing flooding to the project

• Pumps undersized by the consultants and requiring replacement

• Main flow and return pipework connections crossed

There is a lot of work to be accomplished regarding the installation of the chilled water

pipework system before the commissioning stage is reached. Also, the programmed

installation has to fit within the parameters of the Key Dates and Durations Schedule.

Chillers and cooling towers Both of the above can be commissioned to a certain extent before they require

connection to a fully commissioned condenser water pipework system. The condenser

water pipework will be commissioned in the same manner as the chilled water pipework.

The chillers and cooling towers then need to be fully commissioned in order to provide

cooling to the ventilation plant via the chilled water system.

Public health Rainwater and foul drainage The rainwater and foul drainage pipework testing will be carried out and witnessed by the

consultants following sectional completions of the installation. The local authority will also


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want to witness these tests once they are fully complete. The rainwater and foul drainage

pipework testing involves water pressurisation for a given period of time.

The only commissioning involves the foul drainage sump pumps that are located in the

basement level B3 slab.

Instances will arise where bathroom pod wastes are connected to foul drainage riser

stacks.

Both the pod supplier and the riser installer will be responsible for the testing of their own

works. Once the pod has been connected to the riser it will have to be re-tested through

the connection and into the riser. This is fine so long as the test holds up. If the test fails

then problems will arise because neither the pod supplier nor the riser installer will initially

assume responsibility for the leak. This could amount to both companies re-testing their

works, and if an innocent party is discovered then they will want compensating for their

additional work.

A project that consisted of a series of high-rise apartment blocks that collectively

contained over 500 bathroom pods would warrant a regime that ensured the testing was

co-ordinated between all parties. Otherwise there could be serious delays to that

project’s completion as well extension of time claims.

Domestic water supplies The domestic water supply pipework testing will be carried out and witnessed by the

consultants following sectional completions of the installation. The domestic water supply

pipework testing involves water pressurisation for a given period of time.

Following the successful testing the domestic water supply pipework installations require

insulating. This should not be carried out until the pipework has been tested. There are

instances where the pipework will have to be trace heated prior to being lagged.

Domestic water tanks will have to be tested for leakage, booster sets and pumps will

have to be commissioned. In toilets, water heaters need commissioning along with

mixing valves and tap pressure and temperature settings. Flood tests need to be carried

out and finally the system will have to be chlorinated.

Fire protection Wet risers and sprinklers The fire protection wet riser and sprinkler pipework testing will be carried out and

witnessed by the consultants following sectional completions of the installation. The

testing of pipework involves water pressurisation for a given period of time. Following the

successful testing particular aspects of the fire protection pipework installations require

insulating. The insulation of pipework should not be carried out until the pipework has

been tested.


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Wet riser and sprinkler water tanks will have to be tested for leakage, pumps and controls

will have to be commissioned along with fire alarm and BMS interfaces. Flow rates and

pump pressures and drain tests have to be carried out. All of which will have to be

demonstrated to the local authority.

Electrical The termination and testing of an MV cable is a specialist operation that usually occurs at

the same time. MV cables are generally energised within 24 hours of termination and

testing. Failure to do so means that the testing should be repeated before the cables are

energised. The switching on and off of MV supplies is also a specialist operation.

An MV supply has to be energised in order to create a LV supply. It is possible that the

MV supply to a transformer could be energised for a long period of time before the supply

is switched through to its LV panel.

LV cable terminations are not necessarily a specialist operation, but companies tend to

“sub-out” the termination work along with the pulling-in of the LV (&MV) cables.

Before MV / LV supplies are energised the following items need to be completed or in

place: -

• Lockable door to the switch room

• Main earthing cables to incoming utility services.

• Emergency power off buttons installed and working.

• Metering (if remote from LV panel).

• Test LV panel with remote power source (flash test)

• Pressure test (for MV).

• Earth cable readings.

• Phase rotation (supply connections must not be crossed).

• Written power on method statement.

• Signage on 11,000 Volt cables.

• Advise others of power on date.

• Provide warning signs and notices.

• Provide electric shock notice.

• Provide framed schematic drawing.

• Provide rubber mats in front of electrical switchgear and switchpanels.

• Lock off all switches on MV and LV switchgear and switchpanels.

Electrical commissioning will not be carried out until the majority of a distribution boards

sub-circuits or an LV cable installation has been fully terminated. Electrical

commissioning involves testing the cables before they are energised to ensure that there


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are no short-circuits or earth faults. Then following energisation testing to make sure that

the circuit will “trip” in the event of a fault occurring.

Typical electrical commissioning problems A power-on regime needs to be established by the commissioning manager in order to

focus the electrical contractor and prevent power on delays to critical items.

Single phase 230 Volt supplies for dampers or BMS outstations fed from a local

distribution board can give rise to commissioning problems. There could be a situation

where power is required to these items but the distribution board has not been

commissioned. Worse still, it has hundreds of cables hanging out of it that are awaiting

connection.

To prevent situations like this arising the commissioning manager needs to establish what

items are likely to present commissioning problems and address them accordingly.

Emergency power supplies Each individual aspect of the emergency power supplies has to be commissioned

separately before the generators can be fully commissioned. The ventilation, cooling and

fuel oil commissioning will be as explained in the previous ventilation and mechanical

paragraphs.

So by the time the generators are ready to be fully commissioned they should have: -

• Ventilated plant room

• Cooling system

• Completed exhaust

• Automatic fuel supply

• Complete and partially tested electrical mains and controls

The generators will be run-up and commissioned separately before being synchronised

and set to work as a group. They will each undergo a load-test for which a separate load-

bank will have to be brought in.

The controls and remote starting of the generators will have to be tested along with the

functionality testing of the whole electrical systems; culminating with the Black Building

Testing.

Each of these steps will have interfaces with the BMS. The most complicated interface

with the BMS is going to be the load management of the building. This is the

determination and control of the sequential re-switching of the emergency power supplies

to the building following a total power failure.


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BMS In terms of commissioning everything regarding the BMS is critical. But some things are

more critical than others. The most critical items are: -

• Power failure / re-start load management

• Chilled & condenser water

• Ventilation

The BMS has input into the majority of the items that make up the IST / Black Building

Testing. All of these interfaces have to be proved and demonstrated individually and then

globally prior to the IST / Black Building Testing commencement.

In terms of commissioning the BMS has to demonstrate all of the controls / alarms and

graphics as identified in the specification, for all associated plant and switchgear to the

consultant’s satisfaction.

It is only when the BMS is ready for commissioning that the real problems are about to

begin.

A typical selection of BMS commissioning problems for a single plant item are listed

below. (They usually arrive in this sequence and they commence with the appropriate

emotion): -

1. Confusion - with the M&E and fire alarm contractors over who connects to what with

regard to interfaced plant connections.

2. More confusion - with the M&E and fire alarm contractors over who provides what

with regard to interfaced plant connections.

3. Further confusion - regarding exactly what requires power-on for the BMS controls

commissioning of a single item of plant.

4. Amazement /slight anger - when it discovered that the criteria finally determined for

item 3 was actually incorrect.

5. Shock / anger - when it is discovered that there are some critical “points” that have

not been wired.

6. Debate / rage - to determine the blame for item 5.

7. Astonishment - at the discovery that there are not enough “point” connections in the

local “outstation” therefore a further “outstation” is required.

8. Major debate / fighting-talk - to determine the blame for item 7.

9. Joy / surprise - the BMS controls did work.

10. Astonishment / fury - following the discovery that the interfaces with the M&E and fire

alarm contractors didn’t work, usually due to the wrong relays being fitted and

generally resulting in a small explosion.


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11. Bewilderment / time off sick – when the software design does not work in relation to

the plant and the graphics are displaying something totally different as well.

12. Satisfaction – When it is eventually working correctly. That wasn’t too bad! So what

if there were a few snags lets move on to the next item, only another 109 to go.

There they are, the 12 things needed to know about BMS commissioning. Oh! there is

another. The BMS contractor will not assume responsibility for any of them.

Fire alarm The commissioning of the fire alarm will revolve around the functionality of its Cause and

Effect Schedule. This relates to all scenarios involving evacuation when fire has been

detected with various parts of the building. Like the BMS the fire alarm interfaces with

other systems. All of which have to be proved and demonstrated individually and then

globally prior to the IST / Black Building Testing commencement.

The final software for the annunciator panel cannot be completely written until the last

detection loop has been completed. This is because the order in which the loops are

wired will determine the way the software is written, and it cannot be commissioned until

the software writing is complete.

The fire alarm commissioning involves the activation of each individual detector and a

visual inspection of the annunciator panel display to ensure that they are compatible.

The ventilation plant interfaces need to be tested including the smoke extract and

staircase pressurisation. All of the ventilation plant should shut down, with the exception

of the staircase pressurisation fans, which should start up. There are switches on the

annunciator panel that will operate the smoke extract fans at the discretion of the fire

marshal or the fire brigade. Other items that have to be demonstrated include:

• Beam detection

• Fire telephones

• Voice alarm sound levels

• Testing on battery supply only

• All other plant interfaces

• Interfaces with the security system

• Interfaces with lifts

All of this has to be demonstrated to the consultants and local authority’s satisfaction.


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Security The security commissioning involves the setting up and operational testing of all the

devices that it consists of. Including the programming of access devices (cards etc.),

which enable various modes of restrictive access.

The system should fail safe (depending upon the area) in the event of power failure or fire

detection.

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Testing & Commissioning Example