Fastening

• The cables are run in a zigzag or upside down "V" type pattern. They are typically run on only the uninsulated eaves of the home. This is the area most prone to ice dams. The cables can also be run in valley areas on the roof. These areas may be prone to freezing due to heavy shade conditions during the winter season. The cables must be attached securely to a shingled roof so they cannot be pulled loose by any movement of the melting ice dam. A single cable should also be run through the horizontal gutter system to keep it free flowing. Another cable should also be run inside all downspouts so ice cannot form there. A free-flow path must be made for the water or else is will freeze and cause damage to the roof and gutter system.
  
  

Electrical

• Separate GFCI, ground fault circuit interrupter, circuit breakers should be used for the power source of the heating cables. Many of these cables will have wattage ratings which will dictate separate circuits. Most common household wire circuits are rated for 20 amperes at a 120 VAC. Consult the manufactures specifications for amperage rating of the cables and the installation of dedicated circuits. When installing the cables, many manufacturers recommend that the wires are not crossed or come in physical contact with each other. The cables can overheat and perhaps ignite surrounding building materials. Many installations will use outdoor rated receptacles that are installed under the eaves of the roof. The cables are plugged into the outdoor outlets on a seasonal basis.
  
  

Temperature Control

• Most cable packages come with a built in thermostat. These temperature controllers switch the cables on and off in the 40 degree F range. Some heating cables come with no form of temperature control. An outdoor master thermostat will have to be used to efficiently operate the cables. In cases such as these, the thermostat will operate a large contactor, which will energize the cables when the outdoor temperature reaches a certain point. In most cases 40 degrees F is used as water does not freeze until 32 degrees F. The eight-degree temperature difference ensures the water will keep flowing.