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Engineering Laboratory / Fire Research Division

National Fire Research Laboratory

Test_21

Table 1. Test Information
Name
Test_21
Date
Description

Cabinet #8 burn using natural gas line burner inside of cabinet center bay to ignite electical cable. 24pcs. @ 6' length.
Specimen
Electrical Cables
Ignition
Line Burner
Project ID (s)
NRC Electrical Cabinet Experiments
Test Director
McGrattan

Timelapse Video with Heat Release Rate Plot

Table 2. Summary of Test Results
Measurement Value Uc Unit
Peak Heat Release Rate, PHRR
96.5
6.2
kW
Time to Peak Heat Release Rate
21.42
0.07
min
Total Heat Released, THR
174
12
MJ
Gas Burner Total Heat Released, NGTHR
60.23
0.86
MJ
Heat Release Quality Confirmation, HRQC
 Not measured -
MJ/MJ
Net Specimen Mass (gravimetric), NM = Mi-Mf
 Not measured -
kg
Total Fuel Mass Burned, TFM = THR / HOCf
10.28
0.79
kg
Net Effective Heat of Combustion = THR / NM
 Not measured -
MJ/kg
O2 Yield = O2 Consumed / TFM
1.22
0.10
kg/kg
CO2 Yield = CO2 Generated / TFM
1.021
0.086
kg/kg
CO Yield = CO Generated / TFM
0.1129
0.0095
kg/kg
Soot Yield = Soot Generated / TFM
0.0098
0.0040
kg/kg
Baseline Hood Exhaust Flow
14.38
0.43
kg/s
Test Duration = Time(Fire Out) - Time(Ignition)
55.82
0.03
min

Uc = Combined Expanded Uncertainty with 95% confidence level

Table 3. Summary of Test Input Parameters
Parameter Value Uc Unit
Fuel Type
PVC, Natural Gas
 - -
Hood Size
6
 -
m
Effective Duct Diameter
1.975
0.005
m
Exhaust Flow Correction Factor
1.055
0.034
 -
Net Heat of Combustion (per unit mass O2), Ef
12.84
0.51
MJ/kg
Net Heat of Combustion(per unit mass fuel), HOCf
16.90
0.50
MJ/kg
Initial Specimen Mass, Mi (gravimetric)
 Not measured -
kg
Final Specimen Mass, Mf (gravimetric)
 Not measured -
kg
Plot of Fire Heat Release Rate with event markers. Uncertainty bar shown at peak value.
Figure 1. Plot of Heat Release Rate data with event markers and error bars shown at peak.
Table 4. Summary of Observed Test Events
Event Time (min) Description Video Snapshot Image
1
0.00
Ignition
Ignition
peak
21.42
Peak HRR
Peak HRR
2
36.02
burner gas OFF
burner gas OFF
3
54.97
suppression garden hose
suppression garden hose
4
55.82
Fire Out
Fire Out

Table 5. Supplemental Data Plots

Plot of Oxygen Dry Volume Fraction in hood exhaust stream.
Plot of Oxygen Dry Volume Fraction in hood exhaust stream.
Plot of Carbon Dioxide Dry Volume Fraction in hood exhaust stream.
Plot of Carbon Dioxide Dry Volume Fraction in hood exhaust stream.
Plot of Carbon Monoxide Dry Volume Fraction in hood exhaust stream.
Plot of Carbon Monoxide Dry Volume Fraction in hood exhaust stream.
Plot of Radiant Heat Flux data with event markers. r= radial distance from center of hood, h=height above floor.
Plot of Radiant Heat Flux data with event markers. r= radial distance from center of hood, h=height above floor.
Plot of Smoke Laser Extinction Coefficient in hood exhaust stream.
Plot of Smoke Laser Extinction Coefficient in hood exhaust stream.
Plot of Exhaust Duct Mass Flow Rate.
Plot of Exhaust Duct Mass Flow Rate.

Bryant, R. and Bundy, M. The NIST 20 MW Calorimetry Measurement System for Large-Fire Research, Technical Note (NIST TN) 2077, 2019
https://doi.org/10.6028/NIST.TN.2077

NIST Fire Calorimetry Database (FCD)
https://doi.org/10.18434/mds2-2314

Report Process Script Version
NFRL_Report_8.5.9
Last Updated January 17, 2025