F525
UnclassifiedCooling
What This Code Means
Exhaust temperature measurements taken with hand-held infrared instruments are inaccurate by as much as 25% compared to calibrated thermocouples; Inaccurate exhaust stack temperature readings; Infrared instrument temperature measurements off by as much as 25%; Prevented surface temperature reading; Diesel-powered EPS installations do not meet the requirements of 6-4.2
Possible Causes
- •Infrared instruments only measure surface temperatures, not actual gas temperatures
- •Stack insulation prevents surface temperature readings
- •Infrared instrument readings differ with the surface finish of the exhaust stack
- •Using hand-held infrared instruments instead of test cell grade calibrated thermocouples
- •Stack insulation blocking surface temperature measurement
- •Surface finish of the exhaust stack affecting infrared instrument readings
- •EPS installation non-compliance with section 6-4.2
Suggested Actions
- 1Permanently install a K-type (chromium/aluminum) thermocouple in the exhaust outlet elbow
- 2Position the thermocouple tip in the center of the exhaust stream (insertion depth)
- 3Use suitable alloy wiring while minimizing the number of connections to increase accuracy
- 4Permanently install a 'K' type (chromium/aluminum) thermocouple in the exhaust outlet elbow
- 5Position the tip of the thermocouple in the center of the exhaust stream
- 6Exercise the EPS monthly with available EPSS load
- 7Exercise the EPS annually with supplemental loads at 25 percent of nameplate rating for 30 minutes, followed by 50 percent for 30 minutes, followed by 75 percent for 60 minutes, for a total of 2 continuous hours
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