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Cooling Tower Depot
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Expense or Investment? Part 1: Cooling Tower Gearbox Mechanical Systems Monitoring

December
3
2015



Are cooling tower upgrades truly worth the investment or do some serve as a flashy expense? Although it depends on your cooling needs, how will you determine the worth of upgrades? There are many types of cooling tower upgrades and in part one of our four part series we will uncover the details of common cooling tower gearbox upgrades and monitoring systems. It's time to understand your gearbox machinery investments compared to the risks of costly expenses towards your business.



Gearbox upgrades for failure prevention:



  • Oil level switch

    What it does: This switch will automatically monitor your oil levels in your gearbox ensuring that your gearbox stays lubricated at all times, preventing gearbox failures.



    What it can cost you without one: In a perfect world you can rely on your maintenance team to check the oil every month. However in reality your team can get busy, procrastinating oil checks by weeks or months. When gearbox lubrication levels become too low, a gearbox replacement is surly in your immediate future. As your gearbox is being replaced, you will also suffer from cooling tower downtime and performance loss.



    Why have one? The result of having an oil level switch will minimize the expense of maintenance time and management. When oil levels are reduced to a catastrophic level, the switch will shut off your gearbox increasing your gearbox lifespan and preventing performance loss due to a gearbox failure.



    Expense or investment? The oil level switch is a strong investment. This is a small, but important investment and can be installed on any unit for under $1,000 with labor.



  • Oil Filter

    What it does: The oil filter aids gearbox oil filtration, disposing of harmful debris and moisture.



    What it can cost you without one: Similarly to the oil level switch, the oil filter will also prevent a costly gearbox failure and minimize performance loss by maintaining the oil viscosity.



    Who needs one? Any team that struggles to find the time for their maintenance team to change and analyze their gearbox oil. With the oil filter the viscosity of your oil doesn't need to be monitored as frequently, cutting down on your maintenance time, oil analysis costs, as well as reducing the risk of gearbox failure and performance loss.



    Expense or investment? An oil filter is an Investment only when installed with a new gearbox, otherwise it can be costly to include it after initial installation. However, for under $1000 in cost we highly recommend adding it to your order if you are in the market for a new gearbox.



  • Oil sight glass

    What it does: The sight glass device ensures your ability to visually monitor oil levels from outside of the fan stack.



    What it can cost you without one: The risk of not visually monitoring your oil levels can lead to gearbox failure.



    Why have one? This device is the simplest solution to prevent gearbox failure. It will allow you to visually monitor lubrication without completing lock down procedures and cell shutdowns. The oil sight glass will also provide the opportunity for your oil levels to be monitored before the oil level switch shuts down your gearbox.



    Expense or investment? The oil sight glass is such a great investment that it comes standard on every DEPOT brand cooling tower. This is less than a $100 investment that will save you significant time, effort and performance costs.



  • Heater & thermostat

    What it does: A gearbox heater and thermostat will assess the temperature of your oil so the oil doesn't burn out during hot seasonal temperatures.



    What it can cost you without one: Any gearbox lubrication issues can lead to gearbox failure and a pricy mistake.



    Who needs one? We highly recommend this feature to any one whom operates a cooling tower in warmer climates.



    Expense or investment? An Investment for any tower operating in warmer climates. The Heater and Thermostat can be installed for under $1200 and must be installed with a new gearbox, otherwise the investment will not be applicable.



  • Oil pump

    What it does: The oil pump will help pump oil to your gearbox, especially during reduced fan speed operations and will aid with proper gearbox lubrication.



    Who needs one: Oil pumps are generally used with VFD's (Variable frequency drives) because VFD's allow for variable fan speed control. With the opportunity to run fans at any RPM variable, there is a risk that proper amounts of oil cannot get pumped through your gearbox. Thus, the oil pump aids in ensuring enough lubrication.



    What it can cost you without one: By not obtaining an oil pump for your Variable Frequency Drive, you risk gearbox failure and performance loss.



    Expense or investment? An oil pump is a highly recommended investment for VFD's.



  • Oil pressure switch

    What it does: The oil pressure switch compliments the oil pump. You cannot operate the switch without having the oil pump. The oil pressure switch will monitor the discharge pressure of the oil pump. This ensures enough oil is flowing through the oil pump to lubricate your gearbox.



    What it can cost you without one: The oil pressure switch significantly lowers the risk of poor lubrication of your gearbox, again aiding in gearbox failure prevention and avoiding costly shutdowns.



    Who needs one? If you have a VFD (Variable Frequency drive) and have an oil pump, the oil pressure switch completes the package by ensuring that the oil pump is pumping enough oil to your gearbox, especially when fans operate at slower speeds.



    Expense or investment? If you already have an oil pump and are utilizing a VFD, then the oil pressure switch becomes an investment. Your investment comes into play when you're your fans are run at low speeds. Example: during the cold weather months you may allow your fans to operate at low speeds to optimize your tower's energy efficiency. During this time, the oil pump my not have enough pressure to supply your gearbox with enough lubrication causing low oil levels that lead to a costly gearbox failure. Thus if you do not have the oil pressure switch to shut off your gearbox, failure is imminent.



  • Low speed option

    What it does: Having a low speed gearbox option is important to aid in slinging the oil into the upper bearings of your gearbox when the motor is running slower than 450 RPM's. The low speed option is only for single reduction gearboxes, but imperative for VFD applications.



    Why this is important: This addition allows for no minimum input speeds allowing you operate your gearbox as slow as you wish. Having control over variable speeds may help in optimizing the efficiency of your tower.



    Expense or investment? If you have a VFD motor running your single reduction gearbox, the low speed option is a perfect investment for optimizing efficiency and performance when your tower needs to operate at low speeds. The low speed option can be added at any time by your manufacturer.



  • GSU

    What it does: A GSU (Gearbox Service Unit) will allow your maintenance team to less frequently complete gearbox oil maintenance. The GSU checks and monitors your oil levels and oil viscosity, as well as change, filter and analyze your oil all in one step.



    Why have one? With a GSU you do not have to physically complete any oil maintenance and removes maintenance costs such as lab tests to analyze your oil.



    Expense or investment? The GSU provides the lowest risk option for gearbox failure but does have a higher initial Investment than any of the previous options. However over time the GSU can provide a large return as it significantly cuts all other maintenance costs plus optimizes the production of your tower by eliminating the risk of gearbox failure and performance loss. Additionally the GSU will increase the lifespan of your gearbox allowing you to maintain optimal cooling performance.



If you're going to consider a gearbox investment, we personally recommend installing an oil sight glass if you have not already received an install automatically by our team. This is the best investment that you can make for the low cost of $100. However this option still requires visual monthly oil checks. If those monthly oil checks become difficult for your team to find the time to complete, other top investment considerations would be the oil level switch and oil filter. Don't waste precious time and automate your oil viscosity and oil levels to prevent and alert you of pending gearbox failure. Lastly, if ZERO gearbox maintenance sounds like a world you want to live in, we suggest investing in the GSU. A GSU may likely be a future investment consideration as it is has the highest initial cost, but will return the largest gains in production, performance and lifetime maintenance costs for your gearbox.

Need some help determining the right gearbox upgrade for your business that will provide the greatest return?



 
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