Slow temperature rise after installation and a hot ring body are common signs of improper selection or assembly of the heating ring. The following maintenance points are listed for reference by technical engineers.
The applicable temperature ranges of heating rings made of different materials differ significantly. Mica rings are suitable for the medium-to-low temperature range, ceramic rings can withstand higher temperatures but are relatively brittle, and tubular rings are easy to install but prone to local overheating. When selecting a model, it is necessary to check whether the ring's rated voltage is consistent with the supply voltage according to the actual requirements of the heated object, so as to avoid long-term overvoltage operation.
An appropriate gap should be maintained between the inner diameter of the heating ring and the surface of the heated object. If the gap is too large, heat conduction efficiency will decrease and the ring body temperature will rise; if it is too tight, assembly will be difficult and the insulation layer may be crushed. It is recommended to control the fit dimensions according to the values recommended in the equipment manual.
Mica material is susceptible to moisture and vibration. When used for a long time in humid or vibrating environments, insulation resistance may decrease. The insulation resistance between the lead wire and the shell should be measured regularly with a megohmmeter, and any abnormality should be dealt with promptly. Pay attention to moisture-proof storage during shutdown periods.
Lead wires remain in a high-temperature area for a long time and are prone to aging, hardening, or cracking of the insulation layer. Check whether the terminals are loose or oxidized, and avoid excessive force when tightening so as not to damage the internal heating wire.
Under permitted conditions, use a thermometer to regularly measure and record the temperature of the ring surface and the heated object. Abnormal temperature increases or fluctuations can serve as a reference for judging the condition of the internal heating wire and the contact status.
