Because strip heaters and mica band warmers are made from the identical materials, these suggestions will carefully mirror those regarding mica band warmers.
#1 Avoiding Contamination
Moisture is one of the maximum without delay substantive contaminants. If sufficient moisture is present at start-up, the heater will fail as quickly as strength is carried out. Sometimes, whilst the heater has been cooled for a prolonged duration and has been subject to a high humidity surroundings, there can be enough moisture absorbed to reason failure at begin-up. Strip heaters are product of mica, which is very hydroscopic, that means it absorbs water. So, storage in excessive-humidity regions isn’t always endorsed. When insulated lead cord has gotten moist near the strip heater element, the moisture can be wicked into the heater and reason failure. Anytime heaters fail as soon as the strength is provided, moisture is a robust suspect as the offender.
If moisture has been detected, the heater can be baked at 2 hundred°F for about 30 minutes (or longer for large heaters) to dry the heater out.
Oil and different organics can motive heater failure if they get in the metallic sheath, but they behave differently than water. Most oils and organics do no longer behavior power very well as lower temperatures, but carbonize and become conductors at expanded temperatures. Thus, if such contaminants are gift, the failure takes place handiest after the heater has gotten hot enough to motive carbonization. Like water, oil that receives at the lead cord insulation can be wicked into the heater.
#2 Avoiding Over-Temperature
Strip heaters have to be clamped down frivolously and securely to make certain green warmness temperature to the heated surface. If the strip heater is not clamped securely, the warmth generated will now not be transferred effectively to the floor. This will cause the heater to run at a higher temperature on the way to switch its energy. The higher the running temperature, the shorter the lifetime. It is good practice to re-tighten the clamping straps or clamping tabs after the first time that the heater has been used, because the heater will be higher conformed to the floor in the course of its first warmness-up. Anything that stops a smooth healthy of the heater on the surface, such as a surface irregularity, will shorten the existence of the heater. This is due to the fact the net impact of the irregularity is to make a “free in shape” in spots.
As strip warmers warmth up, they may amplify or “grow”. Often instances this could cause the heater to bow or bend up far from the surface and lose touch with the heated floor, thus causing warm spots, which in flip reasons untimely heater failure. A full clamping technique (such as sandwiching the heater among two thick plates) is desired, but the more attachment points or touch factors on a strip heater, the higher. Similar to band warmers, strip heaters want to be in tight, consistent touch with the surface they may be intended to warmness.
Choose the lowest wattage heater with a purpose to preserve the desired operating temperature of the floor being heated and nevertheless offer a brief enough start-up time. Choosing a heater with better wattage than required will bring about the controller turning the heater on and stale to preserve the preferred temperature and a higher working temperature during on-time. These situations will shorten the heater’s lifestyles.
#three Avoiding Excessive Cycling
The way that Thermal Corporation evaluates the lifetime of their personal strip heaters and those from competition is to cycle the gadgets from one hundred fifty°F to 900°F and be counted the cycles to failure. Cycling reduces lifetime because the floor of the element twine oxidizes swiftly at higher temperatures; if the higher temperature is maintained, the oxide coating virtually protects the cord from further fast oxidation, but if the cord temperature is reduced appreciably, the oxide coating breaks off because of contraction and exposes fresh metal to more oxidation. With non-stop biking, the twine diameter is in the end reduced, and the resistance of the detail is expanded to the point that it turns into too warm. At that point, the element wire either melts and breaks open the circuit, or it causes the insulation over the twine to interrupt down causing a quick to the sheath.
#4 Physical Abuse
Never bring a strip heater through the lead wires.
If the heater has post terminals, use two wrenches; one to keep the lowest nut, and one to do the tightening at the top nut.