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Technician Training
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.1 Technician Training
4-6.1 All persons who might be expected to inspect, test, maintain, or operate fire
extinguishing systems shall be thoroughly trained and kept thoroughly trained in the functions
they are expected to perform.
NFPA 4.6-1 requires that testers be appropriately trained. The testing technician should be
certified to at least Level 2 for conducting a single door-fan test and at least Level 3 when
conducting a dual door-fan test. Testers who have completed any part of Retrotec’s training
program are listed on our website at www.retrotec.com, with complete details of their level
of certification.
Technician certification is stored within the CA2001 software, is displayed prominently in the
software and on reports, and is easily viewable by the authority upon request
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.2 Software Conformance
Analysis tools in use by the technician to produce ELA and retention time calculations must
conform to the standard being tested to (either NFPA or ISO). Retrotec’s HA6 DOS software and CA2001 Windows software conform to the NFPA 12A and
2001 standards exactly.
CA2001 conforms to the ISO 14520 standard exactly.
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.3 Room Pressure Gauge Calibration Certificate
The NFPA standard requires that the pressure gauge used to measure the room pressure be
calibrated annually. Experience shows however that unless the gauge has been damaged or
moves unevenly it is generally within 10%.
Calibration certificates for each piece of equipment are stored within CA2001. The witness
should ensure that the gauge being used by the technician has a current calibration
certificate within CA2001 and that the serial number on the gauge matches the serial
number in the software.
The ISO standard recommends calibration but does not suggest the interval. It does require
+/- 1% accuracy. Retrotec recommends annual calibration of all pressure
gauges.
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.4 System calibration
The NFPA standard requires that the complete door-fan system be calibrated every 5 years.
Calibration certificates for each piece of equipment are stored within CA2001. The witness
should ensure that the blower (or blowers) being used by the technician has a current 5-year
calibration certificate within CA2001 and that the serial number on each blower matches the
serial number in the software.
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.5 Field Calibration check procedure
A field calibration check can be requested by the witness to see if the equipment and
operator can actually measure a hole of a known size. This test takes very little time to
perform and is the perfect way to gain confidence in the tester, test equipment, and test
technique.
It is preferable to inform the operator beforehand of the expectation to perform a field
calibration check so the operator can bring the requisite equipment.
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.6 Return Path
There must be a complete and unobstructed flow path from every leak in the enclosure back
to the Door-fan otherwise some leaks may not be measured. This may entail opening
stairwell or elevator doors to floors above and below, neighboring room
doors, and perhaps windows and doors leading outside (if the enclosure under test borders an external
wall).
The witness should ensure that the operator has examined and accounted for the return
paths from all leaks.
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.7 Room and Equipment Set-up
All doors within the zone must be open. The HVAC system and all dampers must be set as
they would be at or during a discharge. A doorway must be selected that opens into the largest and most open space. Applying tape
to seal up the Door-fan panels is OK as long as the doorway is tighter than the panels.
The volume of the room should be calculated on-site using a tape measure or by counting
tiles. Taking volume measurements from blue-prints or site-staff as gospel, without
confirmation, should not be permitted.
Maximum agent height and minimum protected height must be physically (and correctly)
measured on-site. Similarly, the operator must confirm the weight or volume of agent through actual
inspection of the bottles, not by consulting design documents or talking to site staff.
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.8 Static Pressure Check
Before beginning the test, the operator should accurately determine the static pressure.
With the doorway completely sealed and the door-fan completely sealed, the magnitude of
the static pressure must be measured. By opening a small hole (perhaps a single low-flow
plug) and using smoke, direction of the static pressure should be determined.
Relying on the positive/negative sign as read from a digital gauge is very error-prone and
should be discouraged. The origin of pressures above 3 or 4 Pa should be determined and rectified if possible.
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.9 Gauge Set-up
In the case of analog gauges, gauge leveling and zeroing must be completed before any tubes
are hooked up. Most analog gauges are meant to be mounted vertically (usually on doorframe
or in a pre-designed rack or console). Once mounted, the gauges should be carefully
zeroed using small screw-driver and tapped gently to ensure stability. Once zeroed, analog
gauges should be quite stable over the course of the test and need only be spot-checked
occasionally or tapped prior to each measurement.
In the case of digital gauges, zeroing is usually done through a pneumatic switch, either
manually or automatically. Many digital gauges are susceptible to position and once zeroed,
should not be moved. Digital gauges also tend to drift slightly over time as they warm up.
Digital gauges should be zeroed prior to each test measurement. The witness should ensure that gauges are zeroed correctly.
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.10 Flow and Room Pressures Entered Correctly
In addition to ensuring that the gauges are correctly reading the pressures, the witness
should also confirm that the operator actually records the pressure correctly and enters it
correctly into the software.
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.11 Range Selection
The “Ranges” on a Retrotec door-fan refers to the selection of flow-restrictor-plates or
orifices that change the airflow through the blower. Testing on the correct Range is
extremely critical for good results for two reasons.
Often the same room-pressure can be achieved with a number different Ranges (just like a
manual transmission car can achieve the same speed in a number of different gears). For
the best results, the door-fan should be running above ½-speed and the flow-pressure
through the door-fan must be greater than the room-pressure and should be at least double
the room pressure. If these conditions aren’t met, the operator should change to the next
smaller flow range.
If the operator does not input the correct flow-range that the test was conducted on into the
software, the results can be significantly affected. Retrotec’s CA2001 Windows software
displays a picture of the selected Range, which must be acknowledged, before the results of
each test are entered. On older versions of software, the ranges can only be identified by
consulting a pictorial table.
The witness must confirm that the range on the printout or shown in software during the test
matches the range that is actually used by the operator.
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.12 Testing in Both Directions
Rooms must be tested positively and negatively to eliminate bias due to duct leaks and other
static pressures. Testing in both directions is not done due to positive pressures after
discharge.
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.13 Determining the Leakage Split – The BCLA Test
To measure leaks in the lower part of the room is not the same as taping up leaks to pass a
discharge test. The leakage of the whole room, including the ceiling is measured in the first
test, the Total Leaks Test. The lower leaks can be measured separately to get a more
accurate prediction of retention time. The Total leaks test MUST be performed first and
then, and only then, can the BCLA test be performed.
During a ceiling-neutralization/flex-duct test, the witness should ensure that the operator
has indeed neutralized smoke flow across the ceiling. Smoke must be used in this test as
equalizing pressures using a gauge is not adequate.
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.14 Technical Judgment
As a last resort to other BCLA techniques, Retrotec software has a spreadsheet method of
determining leak location. For enclosures with extremely large overhead leaks they may be
passed using “technical judgment” as per the following section:
Section C-1.2.2 (e) of NFPA 2001 App C version 2000 states:
“Enclosures with large overhead leaks but no significant leaks in the floor slab and walls
will yield unrealistically short retention time predictions. Experience has shown that
enclosures of this type can be capable of retaining clean agent for prolonged periods.
However, in such cases the AHJ might waive the quantitative results in favor of a detailed
witnessed leak inspection of all floors and wall with a door fan and smoke pencil.”
It must be understood that, although this test will show the enclosure’s ability to hold agent
in a discharge test, a large measure of the passive fire protection has been eliminated due to
the absence of an upper sealed smoke and fire barrier.
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.15 Yearly Retests
All enclosures must be re-tested yearly if any doubt exists as to whether the room has had
any more holes put in it in the last year.
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.16 Commonly Needed Inert Gas Clarifications
Inert gases are all heavier than air (with the exception of Nitrogen) and will, according to
NFPA 2001, run out of room leaks.
They are not as heavy as halocarbons and usually only run out at half the rate. They do run
out though.
Inert agent enclosures have a very narrow window where they must be tight enough to hold
the agent but loose enough to vent peak discharge pressures. All inert clean agents need relief vent areas according to their manufacturers.
Inert agents still must pass the door-fan tests. If the enclosure has a vent, its area can be checked with the door fan and some vents can be
tested for their ability to open under pressure.
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.17 Enclosure Integrity Test Verification Form
Because there are so many aspects for the witness to keep track of
during the enclosure integrity test, Retrotec has developed an
easy-to-follow check-off sheet. You can also find this form in the
appendices at the end of this document.
Please feel free to copy this form and customize it for your own
organization as you require.
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