Chromalox POO401-9 - Manual (Page 2)

2
HAZARD OF ELECTRIC SHOCK. Any installation
involving electric heaters must be effectively
grounded in accordance with the National
Electrical Code to eliminate shock hazard.
1. Electric wiring to heating elements must be installed
by a qualified person in accordance with the Na-
tional Electrical Code or local electrical codes.
2. Type and temperature rating of wire should be suit-
able for application.
3. Temperature and temperature limiting controls must
be considered when wiring to the heater. Radiant
heaters as well as other applications must have
ground fault protection.
Installation
103 GAMMA DRIVE, PITTSBURGH, PA 15238
Phone: 800-443-2640 www.chromalox.com
Limited Warranty:
Please refer to the Chromalox limited warranty applicable to this product at
http://www.chromalox.com/customer-service/policies/termsofsale.aspx.
© 2013 Chromalox, Inc.
FIRE HAZARD. Failure to comply with the fol-
lowing could result in personal injury or prop-
erty 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 re-
sult in sheath temperatures higher than the recom-
mended maximum since excess temperatures can
cause premature failure and fire.
Generally, sheath materials are limited to the following
maximum temperatures.
Sheath Material Max. Sheath Temp.
Copper 350°F (177˚C)
Iron or Steel 750°F (399˚C)
Chrome or Stainless Steel 1,200°F (649˚C)
INCOLOY ® 1,500°F (816˚C)
MONEL ® 900°F (482˚C)
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 in-
sulation inside the heater. The following contaminants
and others can create current leakage (shock) hazards,
permanent heater damage, or cause heater failure and
therefore, should be avoided.
A. Water or water vapors
B. Grease, oil or oil vapors
C. Corrosive liquids and vapors
D. Noxious or reactive gases
Low Megohm Condition — The refractory material
used in electric heaters may absorb moisture during
transit, storage or when subject to humid environments
that will reduce the cold insulation resistance (low
megohm). Low megohm may result in a high leakage
current to ground and nuisance trips of ground fault
protection equipment. Normally, the megohm value
increases after heat-up. Typical insulation values are
5 megohm or greater on complete assemblies or 20
megohm on individual unsealed elements. It is recom-
mended that heaters with 1 megohm or less be dried
out before applying full power. If dried properly, low
megohm will not effect heater life or efficiency.
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 temperatures should not exceed 350°F.
NOTE: Low megohm on heating elements with epoxy
or hermetic seals cannot be serviced in the field. Typi-
cal resistance values when sealed are 200 megohm or
greater.
FIRE OR SHOCK HAZARD. Moisture accumu-
lation in the element refractory material, el-
ement over-temperature, or sheath corrosion
can cause ground fault to the element sheath,
generating arcing and molten metal. Install
Ground Fault Protection to prevent property
damage.
Operation