WIRING
2. Type and temperature rating of wire should be suitable for appli- cation.
HAZARD OF ELECTRIC SHOCK. Any installation involving electric heaters must be effectively ground- ed in accordance with the National Electrical Code to eliminate shock hazard.
1.Electric wiring to heating elements must be installed by a quali- fied person in accordance with the National Electrical Code or local electrical codes.
OPERATION
FIRE HAZARD. Failure to comply with the following could result in personal injury or property damage.
A.Do not operate heaters at voltages in excess of that marked on heater since excess voltage can shorten heater life.
B.Do not operate heaters under conditions that result in sheath temperatures higher than the recommended maximum since excess temperatures can cause premature failure and fire.
Generally, sheath materials are limited to the following maximum temperatures.
Sheath Material | Maximum Sheath Temperatures |
Copper | 350˚F |
Iron or Steel | 750˚F |
Chrome or Stainless Steel | 1200˚F |
INCOLOY® | 1500˚F |
MONEL® | 900˚F |
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The table above applies to ring, tubular and cartridge element as well as most strip elements.
A.Chrome Steel Finned Strips — 950˚F.
Heaters should not be operated in environments with factors that can destroy the integrity of electrical insulation inside the heater. The following contaminants and others can create current leakage (shock) hazards, permanent heater damage, or cause heater failure and there- fore, should be avoided.
A.Water or water vapors C. Corrosive liquids and vapors
B.Grease, oil or oil vapors D. Noxious or reactive gases
Low Megohm Condition — The refractory material used in elec- tric heaters may absorb moisture during transit, storage or when sub- ject to humid environments that will reduce the cold insulation resis- tance (low megohm). Low megohm may result in a high leakage cur- rent to ground and nuisance trips of ground fault protection equip- ment. Normally, the megohm value increases after
To correct a low megohm condition, remove terminal enclosure cover, gaskets, and terminal hardware. Bake heaters in an oven at 300 to 500˚F for several hours or preferably overnight.
An alternate procedure is to cycle the heater in 10 to 15 minute periods at low voltage until megohm values are normal. Sheath tem- peratures should not exceed 350˚F.
NOTE: Low megohm on heating elements with epoxy or hermetic seals cannot be serviced in the field. Typical resistance values when sealed are 200 megohm or greater.
FIRE OR SHOCK HAZARD. Moisture accumulation in the element refractory material, element
Limited Warranty:
Please refer to the Chromalox limited warranty applicable to this product at
103 GAMMA DRIVE, PITTSBURGH, PA 15238
Phone: | www.chromalox.com |
