Why Is My SmogHog® or MistBuster® Indicator Light Flashing?

One of the easiest ways to tell if your electrostatic air cleaner is operating properly is by checking the indicator light. While a steady indicator light does not guarantee everything is functioning perfectly, a flashing indicator light almost always indicates that there is a problem that should be investigated.

To understand why the light is flashing, it helps to understand how electrostatic air cleaners work.

How Electrostatic Air Cleaners Work

Electrostatic air cleaners such as SmogHog®, MistBuster®, Tri-Mist®, Trion®, and Aerocology® all operate using the same basic principle.

First, an ionizer charges airborne particles using approximately 6,000 to 12,000 volts. The charged particles then pass through a collection cell containing alternating high-voltage and grounded (collection plates) plates. The charged particles are repelled by the high-voltage plates and attracted to the grounded plates, where they remain until the collection cells are cleaned.

A flashing indicator light typically means there is a partial electrical short somewhere within this high-voltage system.

Below are the most common causes.

1. Dirty Collection Cells

The most common cause of a flashing indicator light is dirty collection cells.

As electrostatic filters collect oil mist and smoke, contaminants gradually build up on the aluminum plates. Eventually, the buildup can bridge the gap between the high-voltage and grounded plates, allowing electricity to arc between them.

The solution is to:

• Thoroughly clean the collection cells.
• Allow them to dry completely.
• Reinstall the cells and test the unit.

If the indicator light stops flashing after cleaning, dirty filters were likely the cause.

2. Broken or Loose Ionizer Wires

Another common cause is a broken or loose ionizer wire.

Most ionizer wires are made from tungsten. After years of operation they can become brittle and break, or they may become loose if the ionizer is mishandled during maintenance.

A loose wire can move with the airflow and momentarily become too close to one of the grounded plates, causing the ionizer wire to arc and the indicator light to flash.

Inspect each ionizer wire carefully to verify that it is present and properly tensioned.

3. Damaged Collection Cells

Collection cells that have been dropped, improperly cleaned, or damaged during handling may have bent plates.

If the spacing between the high-voltage and grounded plates becomes too small, electricity can arc between them, causing the indicator light to flash.

Inspect the collection cells carefully for:

• Bent plates
• Physical damage
• Warping of the plates
• Loose spacers or plates 
• Worn insulators allow rods to move back and forth or up and down.
• Burn marks
• Evidence of electrical arcing

Damaged collection cells should be repaired or replaced.

4. Dirty or Damaged Insulators

Cracked, dirty, or carbon-tracked insulators are another common cause of electrical arcing.

Moisture, detergent residue, oil, or carbon tracking can allow electricity to travel across the insulator to ground.

Inspect both the collection cell insulators and ionizer insulators for:

• Cracks
• Wear allowing the parts they hold to move. 
• Heavy contamination
• Carbon tracking
• Moisture

Clean or replace damaged insulators as necessary.

5. Dirty Contact Boards

Dirty contact boards are especially common on electrostatic air cleaners used with water-soluble coolant because water-based coolant is electrically conductive.

If the contact board becomes coated with conductive residue, electricity can short to ground before reaching the collection cell.

Inspect and clean the contact boards whenever the filters are serviced.

Always disconnect power before cleaning or inspecting electrical components.

6. Weak High-Voltage Power Supply

A high-voltage power supply can occasionally fail in a way that reduces its output.

A weak power supply may:

• Cause the indicator light to blink.
• Cause the indicator light not to illuminate.
• Produce insufficient voltage to operate all collection cells and ionizers.

A technician can diagnose this by using a high-voltage probe and reinstalling the ionizers and collection cells one component at a time while monitoring voltage output.

If all cells, ionizers, contacts, and insulators test good but voltage drops as components are reinstalled, the power supply may have failed and require replacement.

Before replacing the power supply, verify that all collection cells, insulators, and contact boards are clean. Excess contamination can increase the electrical load enough to make a good power supply appear weak. This is one of the more difficult problems to diagnose.  Sometimes replacing the power supply or switching all the filters to a diiferent air cleaner to see if they cause problems in a second unit are the only way to know if the power supply is weak and needs replacing.

7. High-Voltage Power Supply Failure

Although less common, a power supply can also fail by producing excessive voltage.

When this happens, the voltage supplied to the ionizer or collection cell may become high enough to arc directly to ground, even when the filters are perfectly clean.

This condition should be verified using a high-voltage probe before replacing the power supply. A voltage more than 10% above spec is too high.

Need Help Troubleshooting Your Electrostatic Air Cleaner?

Troubleshooting a flashing indicator light can range from a simple cleaning to diagnosing a failed power supply. If you are unsure where the problem is or do not have the proper testing equipment, Bee Clean Specialties can help.

Filtration Systems of Troy, Michigan and Bee Clean Specialties have both serviced SmogHog® and MistBuster® electrostatic air cleaners throughout Michigan for many years. Today, Bee Clean Specialties continues providing onsite troubleshooting, preventative maintenance, replacement parts, and repairs for SmogHog®, MistBuster®, Tri-Mist®, Trion®, Aerocology®, and other electrostatic air cleaners throughout Michigan, Illinois, Indiana, Ohio, Wisconsin, Minnesota, and the surrounding Midwest.

If you need assistance troubleshooting your electrostatic air cleaner, contact Bee Clean Specialties. We can help over the phone, provide replacement parts, or schedule onsite service to get your air filtration system operating properly again.