Preventive Maintenance Database

Preventive maintenance is work that is done to equipment and machinery on a regular, recurring basis. A common example would be getting the oil changed in your car. In order to keep most  machines working properly, companies and people create programs based on the manufacturers recommendations for the specific tasks, checks, and adjustments necessary. For a given facility or company, all of the preventive maintenance tasks, scheduling, and tracking is managed through a preventive maintenance program. Some companies use photocopied task sheets, others use spreadsheet programs, and still others use a computer-based program.

I have worked with several preventive maintenance database projects, several commercial products for preventive maintenance, and have even used the old manual programs- but I think that there is much room for improvement in how PM is performed, managed, and tracked.

First, I think a PM database should be easy to load. The supervisor or technician who initially sets up the database should not have to wade through lines and lines of similar tasks in order to set up a PM for a specific machine or piece of equiment. I think that there should be a se of generic preventive maintenance programs pre-loaded, and then the user should be able to add a few custom tasks as needed.

Next, I think the person performing the PM should be able to enter the data into the tracking system live, instead of writing on a printout. I also think that the person performing the PM should be able to make adjustments to the program on the fly. If the system says “change belts” and the unit has been converted to a direct drive system, then the person performing the PM should be able to remove “change belts” from the program.

Finally, system reporting should done through a console, showing tasks completed, tasks modified, tasks pending with percentages. The console should be configurable for administrators, supervisors, and maintenance techs, and you should be able to drill down and view more specific data as needed. PMs should be able to be sorted by category- like location, machine type, person performing the PM, etc.

A good preventive maintenance program supports the equipment and the people who service this equipment- but for all of the PM programs I have seen, the priority seems to be reversed. I think that the people performing the PM end up supporting the people who manage the program, and it becomes more about the tracking and the administration than it is about the actual work that needs to be done. It seems to me that a simple, elegant program that is easy to use and administer would capture the market.

Reading a set of gauges

One of the things with which new HVAC & Refrigeration techs constantly struggle is to learn to take the mystery out of reading a set of gauges and interpreting the information that they are seeing- but the trick is in paying attention to the fundamentals before trying to move on to more advanced diagnostics. Learn about the refrigeration cycle- memorize it, learn to draw it without looking at it- and don’t just draw the components, but be able to say what state (gas or liquid) the refrigerant is in at each point in the cycle.

Remember to practice safety principles- never let any refrigerant come in contact with your skin, inhale it, or get it in your eyes, flash freeze and chemical burns can occur. Also, never vent a refrigerant to the atmosphere, always recover refrigerant when opening or evacuating a system, and be aware that local, national, and international laws apply to the handling of refrigerants, and heavy fines can be assessed if you don’t know what you are doing. Most municipalities require that you take a refrigerant recovery test before handling refrigerant.

The whole point of any refrigeration system is the removal of heat. We are using scientific principles of heat transfer to remove the heat from one area (bedrooms, milk, chicken, buildings) and then reject it somewhere else (usually outside) Refrigeration does this in exactly the same way steam does it, it’s just that refrigerants boil at a temperature lower than water at atmospheric pressure.. It is generally referred to as the vapor/ compression cycle. In the evaporator, the refrigerant picks up heat and boils. this gas is then compressed, and cooled at the condenser, and sent back to the evaporator to boil again.

I know a few old rules of thumb, where techs have some calculation based on the outside air temperature, or something else- which may be enough to get the system running, but may be overcharged or still undercharged when outdoor conditions change.
The best thing to do, is to carry a thermocouple type thermometer, and a pressure-temperature chart and watch what the system is really doing. Remember that the point of any refrigeration cycle (no matter how complicated, or how new the refrigerant is) is all about heat exchange.Here’s a few things to consider:

When charging a system, take temperature readings of the system you are trying to cool. What sort of degree split are you trying to achieve? If you’re running and air handler, with a split system- the best you can achieve is a 15-20F or 8-11C degree split. If it is more or less than this- you are going to have problems down the road. The same thing is true with most walk-in boxes and rooftop units.

Have a look at your suction pressure, and the corresponding temperature. Once you begin adding refrigerant, and you start to get readings on the evaporator section, go back out and read your gauges. Does the suction pressure correspond to a temperature above 32 degrees? If not- is your system designed with a defrost timer or circuit board when appropriate. (A heat pump when charged properly will run a suction temperature lower than 32 degrees during some winter days)

Finally, learn to charge by measuring superheat and subcooling and using the superheat/subcooling method of charging. It is the best way to determine whether a system is properly charged. It requires that you take readings of the suction pressure and two temperatures — “the evaporator boiling temperature at a given pressure and the temperature of the refrigerant at the outlet of the evaporator on the suction line.” Print the linked article and carry it with you until you are 100% sure how to do it every time.

take some time to monitor how different systems run. Walk-in boxes that run on r-22, will have identical pressures/ temperatures to a residential R-22 system when they are first started (indoor temp of the box is 72F or 29C). Get in the habit of carrying a notebook and make cheat-sheets, taking notes when observing how different systems run. Pick up a copy of Modern Refrigeration (Amazon also has used copies) Remember-it’s all about temperatue change, boiling refrigerant, and the transfer of heat!

Commercial door closers and hardware

I recently had the pleasure of trying to adjust a commercial door closer, and I had a flood of memories come back of all the Rixson hardware I used to maintain at Nordstrom. It doesn’t seem like much, but door closers can be somewhat complicated. To get started, there are basically three components to the action of a commercial door.
1. back ckeck. this is what provides force against you when you try to open a door, basically if there was no back check, you could just as easily break a door opening it, as you could slamming it shut.
2. Sweep. This refers to the speed with which the door actually closes when you let go of the door. The sweep needs to be controlled, so that the door doesn’t slam shut.
3. Latch refers to how the door actually closes. If a door is working properly, you can actually observe the door close slowly, and then at the last minute the sweep control will let go to let the door accelerate slightly just enough to let the locking mechanism catch.
I remember spending hours trying to adjust glass doors so that they have the same backcheck, the same sweep, and the same catch speed, and how seasonal changes would wreak havoc on the hydraulics, and cause the doors to open and close at different rates.

Because doors have a tendency to be easily forgotten, I suggest that you include in your regular PM program, a provision to check your doors. things that you want to include may be;

1 Open door to check proper back check, and that door does not swing fully open freely

2. allow door to close, verify that door closes gently

3. observe latch speed to ensure that door and latch mechanism are working properly

4. check closer for visible signs of wear or hydraulic fluid

Every door closer is different, but they all have a way to adjust each element of the function of the door, and you can usually find set screws in the closer for changing these settings.For more information about adjusting and installing door closer hardware, consult your manufacturer, or check out http://hubpages.com/hub/Door-Closer-Adjustment for a pretty good overview of how they work

Thoughts from a site visit

I reviewed a site today to create a PM program for their HVAC systems, and I have to say that I was rather impressed with their systems.

They were using a ground source heat pump system with Honeywell controls, Yaskawa variable-frequency drives, McQuay water-source heat pumps, and two AAON units on the roof for fresh air and supplemental AC in the warmer months.

Although they haven’t received LEED certification yet, This building is still a long way from older less efficient systems. Another thing I noticed was the attention paid to safety in the installation of thier equipment. All of the equipment was accessible by catwalks and access doors, and you could tell that quality engineering went into the design of their building.

I can’t brag too much about the building yet, and since we’re only bidding on the project, I’ll have to wait before I say too much more about it!

Great idea from Construction Protection Systems

Managing a buildout or remodel in an occupied space can be a big enough headache, but trying to keep contractors from destrying common areas during the process can become a full-time job, and as a maintenance professional, you’ve already got PMs that need to be done, service requests, and other tasks on your schedule.
One great item I just found mentioned in Total Facility Manager as their product of the month is the 123 Door Shield from Construction Protection Systems llc.

the 123 Door Shield protects doors from dings and scratches during remodeling and interior buildouts.

The 123 Door Shield can be re-used, stacks flat, and can be recycled if you decide you don’t need it any more. No actual adhesive touches the door, as the pre-fab construction simply slips over the door. Calbrated perforations for door handles and door hardware make it easy to accomodate different locations for handles and locks.

Manufactured in Colorado, the 123 Door shield comes in packs of 5, and can be pruchased through local distributors of doors and door hardware. Click on the picture above for more information.

Highlights from ASHRAE’s AHR Expo

Expo floor shot

We just Got back from the show tonight, and I wanted to highlight some of the exhibits that I saw there. Since this was my first AHR Expo, I really didn’t know what to expect going into it, and I have to admit that I was impressed with the number of manufacturers that were represented at the show.

Johnson Controls probably wins “the biggest exhibit with the most hype” award, giving out free gadgets with drawings and a giant puzzle for the crowd to work on. They were also the first one to get an email out to me with more information after scanning my badge at the show.

I was a little disappointed with the lack of actual zigbee devices, while the zigbee-bacnet connection was pretty big news. Bacnet has decided to accept the zigbee protocol for wireless solutions, and IEEE (the creators of the zigbee protocol) has also decide to reciprocate. This should allow manufacturers to design hybrid systems that combine the best of wired solutions, with new wireless innovations.

A real example of a company moving forward with wireless is Honeywell, who was there with a large “hype booth” but also had a smaller booth tucked over in the corner exhibiting a new CO monitoring system that uses zigbee wireless sensors with a hybrid CO/ CO2 monitoring system.

Another small vendor with a really great product called Gasflux uses a liquid flux tank attached to an oxy-acetylene rig to create a really clean brazing technique. I’m sure this will catch on with refrigeration mechanics and welders alike.

Green was a big deal this year, as was to be expected- from variable frequency drives, to high efficiency pumps, solar collectors, and heat recovery devices, finding ways to reduce energy costs has become the holy grail of the HVAC industry. The thing that I like about ASHRAE is that they are making real efforts to gauge and measure actual energy savings, and their OPMP certification is a step in the right direction to help facility managers decide on the cost benefits of adopting an energy strategy. (I took the test, I guess I’ll find out in a few weeks if I passed or failed!)

Finally, the big news this year at ASHRAE was globalization- Many Chinese manufacturers were represented, as well as more european manufacturers as well. With efficiency and cost becoming hotter issues, manufacturers that can create small, modular high-efficient equipment at a lower cost will begin to stake out their own segment in the market.

BACnet has huge presence at ASHRAE

BACnet is making a real effort to become the communications protocol for HVAC/ Security/ BMS systems management for commercial applications, and they announced at the trade show that they will be supporting the Zigbee wireless protocol as well.

With Honeywell, Johnson controls, Siemens and several other large controls companies in compliance with BACnet’s standards, hopefully the dream of true interoperability can be realized, but there are a few hurdles that still need to be jumped before anyone can claim that it will be easy to implement.

BACnet is recommending that manufacturers use ip routing for their packets, while some manufacturers are still sticking with older networking protocols citing things like security and legacy as reason why they haven’t switched.

Second, controls specifiers and designers still struggle with issues of cabling, Some have gone with the RJ45 for ethernet cabling, while other systems are still using older connectors like RS232 connectors(my latest Dell laptop doesn’t even have an RS232 connector)

Hopefully, their entry into the Zigbee Alliance will help them modernize these systems and truly bring this technology into the modern era. If they can’t do it, someone will.

AHR Expo this week

I’ll be attending the AHR Expo hosted by ASHRAE this week in Chicago at McCormick Place.

This is my first day working full-time for my new venture Enercient a wireless HVAC monitoring system, so we’re going to the AHR expo to see the latest and greatest in HVAC wireless monitoring and controls.

I’ll be posting to brighkite with pictures and updates, and plan to report on new technologies, equipment and controls that we see at the show.  Maybe we can get some quotes and pics from the showroom floor. I’m also taking the OPMP certification test on Wednesday at the show, so wish me luck.

Later, We’ll be able to do more in-depth reviews and post material covering the show.

maintaining pumps and motors

Many pumps, circulators and motors run quietly day after day sitting in the corner, and the technology has become so reliable- it’s easy to forget that there are still things that can be done to extend the life of the pumps and motors in your plant. Here’s a few things that you can start doing now:

1. monthly preventive maintenance and inspections Pumps and motors have internal moving parts, and moving parts can eventually cause heat and friction- which eventually leads to breakdowns and system failures. The best way to prevent this is to make sure that bearings, shaft hubs, and oil ports are lubricated regularly. Consult your O&Ms for the right frequency, but after a while you will learn what the best schedule to follow is. Also, keep surfaces clean and free of dust as dust buildup can cut off air circulation through cooling vents on motor housings.

2. Take readings and get to know normal operating parameters Motors will give another clear indication that they need care, because amp draw will increase as bearings begin to fail. friction causes a strain on the motor that was not there when it was new and moving free, so the motor will need to work harder to do their job- this immediately shows as an increase in amp draw, so take regular amp readings while the pump is in operation. Remember that you are working around live voltage to do this, so always use proper safety procedures during readings and inspections.

3. Duty cycling Many pumps and motors are installed in  groups or pairs  so that they can provide backup for failures and shutdowns, however it is important to cycle the backups because bearings and seals can develop flat spots if they are left to sit without running. Some engineers and operators will run their pumps in an alternating lead/ lag switching back and forth with each inspection- sometimes this must be done by hand, and sometimes its just a matter of throwing switches in a panel. If you are unable to put pumps into service, and you know that they will be out of service for an extended period (summer/winter) put it on your schedule to operate pump shafts by hand regularly.

Finally, and I’ve mentioned this in other posts and I’ll probably end up saying it again- always listen to your plant and get comfortable enough to put your hands on your equipment as you walk through. If you get used to the way your equipment sounds, you will notice when that sound changes. If you know your normal operating temperatures, you will know when those tempertures begin to rise. These are the things that will distinguish you in your career- and make you a better mechanic.

Starting the New Year Correctly at Your Facility

After the holiday trimmings are all packed away, and you’ve completed those end of year tasks like budgeting, forecasting, or just surviving the holidays, the New Year is a chance to start out fresh. You’ve got that new desk calendar from your favorite vendor, or that shiny new pocket calendar is riding in your back pocket waiting for some new tasks and appointments.The problem is, after a few weeks, those tasks on your office white board never change, and you get caught up in the usual rush to respond to emergency and “immediate need” ticket work, while longer-term projects collect dust. Here’s a few tips to keep the momentum going.

1.Learn to get in the habit of carrying something to jot notes, and when someone asks you to do something, pull out your notebook, daytimer, (whatever works best- I like the moleskine) and tell them you’re busy right now but you’ll get back to them in a couple days. This will help you start managing your time better, and keep you from having 6-7 open/incomplete tasks on an ongoing basis. The real trick here is to check your lists- and follow up on promises in a reasonable time.

2. Leave notes and communicate updates. When you complete a task that someone has asked you to complete, leave a sticky note, or a post-it for them to let them know you followed through. When you aren’t finished doing something, but you’ve done something to move a project along (like calling a vendor for a delivery update) A quick note to tell someone that you changed a light,made a phone call, or painted a door frame will go a long way to remind people that you’ve actually done what you’ve been asked to do.

3. There’s no shame in admitting you can’t complete something once you find out it is bigger than you thought. An example might be where you decided to tackle a door refinishing project, thinking that you’d have time to refinish doors in your facility. You’ve done 2 of them, and they look good, but it took you 4 weeks to complete the two that you’ve done, and you have 30 more. If you approach your property manager and let them know that the project is taking longer than you thought, and give them the option of deciding what to do next, they might; authorize overtime to complete it after hours, allow you to solicit bids from a pro, or you might find out that it is not a high priority, and they don’t mind waiting.

Finally, if you are not giving your property manager,  board, or supervisor a regular report (at least monthly) of your activities you should get in the habit right away. Your monthly report can include things such as; Completed Tasks, Work waiting approval, Open work orders, Parts on Order, etc. Just because you know that something is in process, doesn’t mean that everyone else does, and it is your job to tell them.