You are here: Home > FAQ > Technical FAQ's


When should I use a braided cable, and when should I use an overjacketed cable?

Braided cables are intended for use in dry areas. The braid is tinned copper, which allows for maximum conductivity but can deteriorate over time when exposed to moisture. For wet areas, select an overjacketed cable. In the commercial products, overjacket is polyolefin; in industrial and high temperature cables overjacket is flouropolymer, which also offers superior corrosion resistance.

I see cables listed for 240 volt use. What if I only have 208 volts available?

Cables rated for 240 volts can be used at any available voltage from 208 to 277. There will be slight variations in heat output, depending on the voltage applied. The Heater Design Data Sheets include selection guides at nominal voltages (120 or 240) as well as 208v and 277v.

How do I know what category of cable I should use?

Commercial cable products have UL approval for ordinary (non-hazardous) areas. These cables have 18 gauge bus wire and are ideal for freeze protection or for temperature maintenance up to about 150 degrees F. For the same temperature ratings but with 16 gauge bus wire for longer heater cable segment length and additional UL & FM approvals for Class I Division 2 hazardous locations, use an Industrial cable product. Both Commercial and Industrial products have a maximum intermittent temperature exposure of 185 degrees F. For higher maintain temperatures (up to 250F) or higher exposure temperatures (up to 375F) select a cable from the High Temperature product group.

If I am using heater cable on a pipe, why do I need insulation?

Without insulation the heat produced by the cable will dissipate into free air, with little or no effect on pipe temperature. Even a small amount of insulation will help keep the heat from the cable on the pipe. (See the watt loss charts for more specific information)

Okay, then if I insulate the pipe, why do I need heat tracing?

Good question! Insulation slows the loss of heat to ambient air, but does not stop it. The heater cable is used to offset the heat loss through the insulation.

Do pipe supports and valves need any special treatment?

Yes. Pipe supports and valves will lose more heat than straight sections of pipe, so additional cable is required at these locations. The installation manual that ships with your order includes a table to let you know how much extra cable to use.

Can I install heater cable on top of the pipe?

Well, you can but we sure don’t recommend it. For one thing, a heater on the top of the pipe is more susceptible to mechanical damage -- having a tool dropped on it or someone walk across it. Also, as a pretty good general rule if the pipe is only partially filled, the fluid tends to be in the lower quadrant of the pipe. (At least on planet Earth.) Looking at the cross section of the pipe as a clock, four o’clock or eight o’clock are ideal.

How do you know whether to use aluminum or fiberglass tape?

Aluminum tape is typically used for plastic pipes and tanks to aid heat distribution. It is also required when installing heater cable on steel tanks. Fiberglass tape is recommended when attaching heating cables to stainless or metal pipes. Fiberglass tape is applied across the heater cable at every foot; aluminum tape is applied on top of the entire span of heating cable after it has been secured to the pipe with fiberglass tape.

If the heater cable is self-regulating, do I need a controller?

That depends on how precisely you need to control the temperature of the pipe. If tight control is required, a line sensing device is best. For freeze protection applications, an ambient sensing controller often used with self-regulating heating cables. When using a line sensing controller, a separate controller should be used for each unique flow condition.

How should I decide whether to use ambient or pipe sensing controllers?

Ambient sensing controllers typically offer a simpler installation and lower material cost, since one thermostat can control multiple pipe segments. However, energy costs will be higher, since the controller does not respond to changes in pipe temperature. (Think of the heat in your house -- if the thermostat was on the front porch instead of in your living room, the heat would be on most of the winter, keeping the house much warmer than needed and energy bills higher than necessary.)

Pipe sensing controllers are more precise and energy efficient, but can have a higher initial material and installation cost since a separate controller is required for each unique pipe size and flow condition. Controlling multiple pipes with a single pipe sensing controller can lead to freeze ups.

For a single pipe run, pipe sensing controllers are usually the best option. For mutliple pipes, consider the balance between upfront cost and long term operating costs. For long pipe runs or where total electrical loads are high, the initial cost differential for pipe sensing controls can be an economical choice in the long run.

What is a “self-regulating” heater cable?

A self-regulating heater provides a watt output that increases as temperatures fall and decreases as temperatures rise. The wattage rating given for each cable is the output of that heater at nominal voltage (120 or 240) at 50 degrees Fahrenheit. Above 50 degrees, the cable will put out less than its nominal wattage; below that temperature, it will produce higher than nominal wattage. As the cable heats up, output approaches zero.

Is ground fault protection required for heating cable systems? What type?

The National Electrical Code requires a ground fault protection device for any electrical heating cable circuit. There are two basic types of ground-fault protection.

GFI devices are personnel protection with a 5 to 8 mA trip level. Typically this type of protection will cause nuisance tripping when used with heater cables.

GFEPD (ground fault equipment protective device) is used for equipment protection, with a trip level of 30 mA. This is typically used for heater cable applications and is specifed by the N.E.C.

This protection can be provided by using a GFEPD branch circuit breaker to power the heater cable, or by using an electronic controller which includes ground fault protection. See the
electronic thermostat section for product options.

What is the effect of wind on heat traced lines?

An insulated pipe is not affected by wind chill the way a human being is. In absolutely still conditions, a thin layer of air around the insulation helps reduce heat losses, but once air is moving that layer is gone. Heat loss calculations for a given pipe at 5, 10, 25, or 50 mph wind do not vary a great deal.