Watlow Electric 316-42-5-1 Benutzerhandbuch

WATLOW IND.n  # 6 INDUSTRIAL LOOP RD. n HANNIBAL MO, 63401n PHONE 573-221-2816 n FAX 573-221-3723 

 

 

 

•  Check to make sure that heater received is the same as that ordered.  

•  Watlow heaters are built to comply with UL and CSA  dielectric requirements, it may be necessary due to 

atmospheric conditions / humidity, to perform a dielectric test prior to startup. (Refer to megohm test 
under Installation section)        

 

 

Electric heaters are inherently dangerous!! Care should be taken to read and completely understand the 
Installation and Maintenance manual before installing and wiring the heater. Any installation and 
maintenance performed on the heater shall be done by a qualified electrician, in accordance with the 
"National Electric  Code" and other electrical codes as they apply. It is the users responsibility to ensure that 
the heater being used is properly selected and installed in the application. 

 

 

!

  

The Caution Symbol (exclamation point) alerts you to a "CAUTION", a safety or   

 

functional  hazard which could affect your equipment or its performance. 

 

 

The warning symbol (lightning bolt) alerts you to a "WARNING",  a safety hazard which 
could affect you and the equipment 

 

 

  

 

Proper heater selection and installation will result in efficient heat transfer, safe operation, and long heater 
life. 
 
1.  Megohm precheck  

During shipping and/or storage, the possibility of moisture absorption by the insulation material within the 
element is possible. To ensure proper megohm values a minimum  500 VDC megohm meter (Megger) 
should be used to ensure that the megohm reading between the heater terminal and the heater sheath is 
more than 10 megohms when the unit is at room temperature.  
 
If several units are interconnected, the megohm of the heater is obtained by taking the reading and 
dividing by the number of interconnected elements. This reading should be greater than 10 megohms. 
 
If a low megohm value exists, two alternative methods can be used to remedy the situation. The best 
method is to remove all terminal hardware including thermostat if provided, and bake out the heater at no 
higher than 250°F (120

°C)  overnight or until an acceptable reading is reached. The second method is to 

energize the unit at low voltage in air until the megohm is at an acceptable reading. Care should be 
taken to prevent the heater sheath from exceeding 750°F     (398

°C)  for Incoloy® and steel elements 

and 400°F (204

°C) for copper elements. Both of these methods should be performed with the heater out 

of the tank. The  orientation of the heater in relation to the tank should be observed in order to reposition 
the heater properly. This is especially important if a high limit thermocouple is provided. 

 

The use of temperature controls to regulate heating process and prevent heater over temperature is 
highly recommended to ensure safe heater operation.  It is the users responsibility to ensure safety of 
the installation.