Repair or Replace - What are your options?
Precipitator T/R sets are among the most reliable, low maintenance equipment at any electric utility or industrial plant. Their stated lifetime is 20-25 years, but we have seen many units in continuous operation for over 40 years. When you factor in the lack of preventive maintenance they require (no consumables to replace, no bearings to lubricate, etc.), it's easy to take them for granted. Until they fail. Then what?
If you’re fortunate to have a large precipitator with dozens of T/Rs, the loss of one unit won’t affect your opacity significantly. Adjusting a couple of settings will keep you running until the repaired or replacement T/R arrives. However, if you only have a few high voltage units on your roof, the loss of one can have serious consequences on your ability to meet your permitted emissions.
So, what are your options? The table below sorts out the various choices, comparing relative cost, leadtime and length of warranty (this example assumes a standard T/R replacement cost of $15,000):
T/R set Repair and Replacement Options
| Option |
Cost |
Leadtime |
Warranty |
| Emergency Repair |
$5,000 - $20,000 |
1 week |
1 year on replaced parts |
| Non-emergency repair |
$7,500 |
3 weeks |
1 year on replaced parts |
| Complete Refurbishment |
$11,000 |
4-5 weeks |
2 years on entire unit |
| Standard T/R replacement |
$15,000 |
6-8 weeks |
2 years on entire unit |
| Exact T/R replacement |
$18,500 |
10+ weeks |
2 years on entire unit |
| Technology upgrade (SMPS) |
$25,000 |
4-6 weeks |
3+ years on entire unit |
That's not a misprint - an emergency T/R set refurbishment (assumes core, coil and rectifier are damaged) can cost more than a brand new unit. While it may appear at first glance that a complete refurbishment provides the best overall solution with respect to these three factors, the right choice for you will depend on your budget, urgency, and maintenance philosophy.
Although there’s no way to completely prevent an emergency repair, there are some things that you can do to minimize your risk:
- Monitor their performance. Observe peak voltage values, sparkover rates, and secondary voltage and current to ensure they’re working within the manufacturer's specifications.
- Schedule a check-up. If you have manpower constraints that prevent periodic checks, have a qualified technician inspect your T/Rs. Contact Don Farrar, our Service Manager, to schedule an appointment.
- Take an oil sample. The best way to diagnose a T/R set’s health is to perform a DGA (Dissolved Gas Analysis). An initial DGA will provide a baseline for the relative condition of your T/Rs, and subsequent tests can assist in prioritizing repairs or service. More information about DGA can be found here.
|
