IEEE 515:2011 pdf free download – IEEE Standard for the Testing,Design,Installation, and Maintenance of Electrical Resistance Trace Heating for Industrial Applications
A sample of the heating device with all integral components shall be placed in a tap water flow and drainapparatus as shown in Figure 1.For surface heating units, a unit with cold leads shall be used. The waterflow shall be initiated, and the heating device and integral components shall be completely immersed.Atthat point, the water flow is stopped and the heating device is energized.The apparatus is then drained.Thetotal time from the initiation of water flow to the completion of draining shall be no greater than 4.5 minand no less than 2.5 min. The heating device shall continue to be energized for 30 s after the water has beendrained.The heating device is then de-cnergized and water flow is initiated for the next cycle. The test shallbe continued for a period of 24 h.After completion, the dielectric test in 4.1.1 and the insulation resistancetest in 4.1.2 shall be successfully completed. The immersed connections of the heating device shall beinspected to verify no evidence of water ingress.
4.1.6.1 Primary test
Three randomly selected samples representing the maximum output of all trace heaters or surface heatingunits under evaluation shall be tested. If the type of trace heater or surface heating unit has different levelsof rated voltages and wattages, then three samples each shall be selected that represent 1) the lowest ratedvoltage level and the maximum rated output, and 2) the maximum rated voltage and the minimum ratedoutput.
The samples shall be terminated according to the manufacturer’s recommendations，such that a heatinglength of at least 600 mm or representative surface heating unit dimensions is provided. The agingtemperature of the test shall be the maximum declared maintain temperature of the heating device.Thesamples shall be conditioned, while energized, at the aging temperature for 120 h±24 h.The initial outputof the samples is then to be determined by one of the three methods given in 4.1.11, with the exceptions ofsample length and number of test temperature points for item c) of 4.1.11.For this case, the samples shallbe evaluated at rated voltage and at the manufacturer’s stated reference temperature for the rated output.The output shall be within the manufacturer’s stated output range.
The samples shall be attached to a fixture or suitable heat sink as described in item c) of 4.1.11 andinsulated accordingly.The pipe or heat sink temperature shall be set to the specified aging temperature andmaintained with 土3 °C plus 1% of the temperature reading in degrees Celsius. Circulating fluid or extcrnalheating may be used to raise the fixture to the aging temperature. The samples shall be operated at ratedvoltage.The power supply shall be attached to a i5 min cycle timer such that the samples are energized forl2 min and de-energized for 3 min. The samples shall be exposed to this conditioning for 32 weeks(5376 h).
For heating devices with an intermittent temperature exposure rating, the samples are exposed to the sameconditioning for 32 weeks, except for an 8 h excursion once each week.At the beginning of the 8 h, thesamples shall be disengaged from the cycle timer. The pipe or heat sink temperature shall be increased to atemperature equal to the manufacturer’s stated intermittent exposure temperature. The time allowed toincrease the temperature should be no greater than l h.After 7 h from the beginning of the excursion, thepipe or heat sink temperature shall be decreased back to the aging temperature, again allowing no morethan 1 h for the operation. Where the intermittent temperature rating is based on the heating device beingenergized,then the heating device shall be continuously energized during this temperature excursion,except during cool down back to the maximum maintain temperature. Where the intermittent temperaturerating is based on the heating device being de-energized, the exposure cycle is conducted in a de-energizedcondition. At the end of the 8 h excursion，the samples shall be reengaged to the cycle timer. Theexcursions should occur on the same day each week.
At the end of the 32 weeks of operation at the continuous rated temperature, the output of the samples shallbe determined by the same procedure as used for the initial readings. The heating device samples shallmaintain a power level within plus 20% or minus 25% of the initial measured output.