Watlow Start-Up Guide for Electric Heaters

Ensuring the proper installation of a Watlow® electric heater is crucial for maintaining high performance and longevity within industrial applications. In this article, we'll delve into the two most critical factors for a successful installation: following the installation guide and using the correct tools. By adhering to these guidelines, you can enhance the efficiency and reliability of your Watlow heater.

Check the Heater and Its Elements

Before installing a new Watlow heater, it's crucial to inspect all heating elements and visible components of the assembly for any defects resulting from shipping. Even minor bends or nicks can adversely affect the heater's overall performance and limit its service life.

Perform a Megohm Test

After confirming the unit's integrity, conduct a Megohm test to measure the insulation resistance of the heating system. Moisture or dampness within the insulation can cause the system to fail this test.

A Megohm test uses direct current voltage to test the insulation resistance of the heating unit. Insulation resistance is the ability of magnesium oxide (MgO) to keep electricity within its bounds. There should be complete resistance between the inside and outside of the insulation. What is being measured is the resistance from the heater to the ground.

If the Megohm test reveals that the heater does not perform in the acceptable range, which may indicate moisture or low resistance, a "bakeout" process may be necessary. This involves elevating the heater's temperature to dry it and clean it before final installation. Sometimes, a vacuum is required to remove loose particles.

Installation with Proper Tools

Choosing the right tools is vital for a successful installation. Some heaters like the flange heater, might require different tools than the screw plug heater. Always consult the installation and maintenance manual to ensure you're using the correct tools to avoid potential damage to the heater's welding and wiring.

Consult the Wiring Diagram

Following the Watlow installation guide, attaching the wires properly requires a threaded stud and a threaded nut. First, remove the threaded nut off the jumper, add a rain connector onto that wire and then put that connector over the threaded stud. That nut needs to be tightened but be careful not to overtighten the nut. Torque values for nuts are eight in/lbs. for nuts that do not go over a jumper and 20 in/lbs. for nuts that go over jumpers.

watlow_heater
Shop Watlow Heaters >

Once the Megohm test is successfully completed, and the wires are securely attached, the construction phase of the heater installation is complete.

Perform the Proper Ohm's Test

Conducting an Ohm's test is the final step. This test, carried out using an Ohmmeter, checks for electrical connectivity issues with the heater. Follow these steps:

  1. Ensure the Ohmmeter has a battery
  2. Zero the meter by touching the leads together and adjusting the reading to zero ohms.
  3. Disconnect the electric heater to prevent damage or electrocution.
  4. Adjust the Ohmmeter's scale (tens, hundreds, or thousands) based on the heater's requirements.
  5. Touch the probe's opposite ends of the circuits and compare the reading with the expected resistance of the heater.

Unlike the Megohm test, which assesses insulation, the Ohm's test focuses on electrical conductivity. This test is especially useful as a maintenance check for heaters that have been in use for an extended period.

Installing a Watlow electric heater is crucial for achieving optimal performance and longevity. By diligently following the installation guide, using the correct tools, and conducting essential tests like the Megohm and Ohm's tests, you can ensure that your Watlow heater meets the highest standards of reliability and efficiency from the start and throughout its service life.

The article can be found here.

IES Tech Sales is a partner and distributor of Watlow. For more information, contact us today.