Vehicles usually come to us when there are  problems or complaints about them. Our job as mechanics is to verify the complaint, find the cause and fix the problem. There is a very easy method that helps diagnose the problems: the K.I.S.S method. This means Keep It Simple, Stupid. It’s not meant to be offensive, it just means that often the basic problems are not ruled out before moving on to more complicated ones.

In one case, we were looking at a truck that had an alternator problem. We did the basic checks and found that it was not charging properly. We then discovered there was not any voltage seen at the alternator to energize the field. Now, on this particular vehicle this is controlled by the PCM. Immediately we thought we should replace the PCM to solve the problem.

After a little more diagnosis however, we found that there was in fact an electrical output at the PCM going to the alternator. This output voltage was not found at the alternator, telling us that the problem was a break in the wire. After cutting open the  harnesses and tracing the wire,  we discovered a spot in the wheel well were the harness had rubbed through:

A quick repair to the wiring was all that was needed. This is  a common spot for wiring to rub through. I’ve seen  it on a few other trucks with different problems that  led to this same spot. The harness was a main harness for the engine, so it does not cause this exact problem very often.

Environment Canada has a weather collection project called “COOLTAP.” It is a weather-tracking website where daily weather data is entered and tracked. Grand Rapids has been doing this for over 40 years!

Found inside the white cabinet are two thermometers; one senses the maximum temperature, and the other the minimum. Both are reset after the data has been recorded. (The maximum thermometer is shaken down, while the minimum is gently tipped to reset.)

Precipitation (both rain and snow) is also collected. Shown below is the container in which rain is caught. The main tube holds 25mm, but can spill over to an outer tube. We can collect over 100mm of rain!

We collect the weather twice daily; once at 6 a.m. and again at 6 p.m. We record the weather online at the COOLTAP website, and also in our own spreadsheet.

The control room reported a high temperature alarm on Unit 4 230kV transformer, B phase. Our transformers have two temperature alarm points. If the first point is reached, the first stage fans are automatically called to start. If the second point is reached, the second stage fans are called to start. Both stages will continue to run until the temperature drops below the alarm points.

Upon investigation of the transformer, none of the cooling fans were running. When troubleshooting, the first thing you check for is power. We immediately found that three control fuses were blown. Troubleshooting does not end at blown fuses, as they are overcurrent protection. They must be replaced, but this is not a permanent fix to the underlying problem: something is overloading the circuit. During troubleshooting, we keep the fuses removed to keep the circuit de-energized. Pictured below is the empty fused disconnect.

This was an excellent opportunity to exercise our print reading skills, and to find all the possible problems. After the function of the circuit was clearer, we found two contactors were blown. Contactors are what make automatic starting/stopping of the fans possible. Pictured below is one of the blown contactors. The black screws show where it blew up.

Here is a view of the control panel with the blown contactor removed.

The contactors were replaced, along with the fuses. We tested each of the eight fans individually, and checked their individual full load amp draw with a clip-on ammeter. We set everything back to auto, and the alarm cleared once the temperature returned to normal.

The cause of the problem was traced back to a faulty contactor stuck in the closed position.

Often in this job we are required to complete tasks that are outside the electrical realm.

Hydro has its own fleet services department which takes care of any routine or major repairs that any of our vehicles may need. However, once a week we perform basic safety inspections on our vehicle as preventative maintenance.

Since we use our truck daily around the station and on the highway, it is important to do a thorough check of wheel lug tightness, tire pressure, and the condition of the tires and rims. The oil is checked, along with power steering fluid, coolant and transmission fluid. We check that the headlights, high beams, hazards, working lights, brake lights and reverse lights are all functional. We test the horn, and check that the first aid kit is stocked, and the fire extinguisher is present.

After all the inspections are done, the truck gets vacuumed and washed.

I am pleased to report that the electrical shop truck passed with flying colours today!

Working at St. Boniface College has been interesting, in a nostalgic way.  This job incorporates some of  the latest, breaking technology when it come to heating and cooling a building.  Yet at the same time we are using some of the most tried, tested and true plumbing systems around. 

The majority of construction sites today use plastic drainage and sometimes plastic water lines.  But this job takes a step back in time using only cast iron and copper drainage.  In fact, no plastic is being used on this job.  Some people may think that this type of construction is archaic, but in many respects it can’t be beat.  One benefit is that the drainage system is rigid and sturdy.  Many times when you receive plastic pipe from the plumbing wholesaler, it is bowed because of sitting outside in the hot sun.  Not so with cast iron.  Another benefit is that cast iron is quiet.  In residential applications, you can always tell when someone is using a plumbing fixture because you can clearly hear the water moving through plastic pipe.  Cast iron is almost silent. 

And probably the greatest benefit to using cast iron and copper is that it is very easy to “fire stop.”  This means that there has to be a way to control smoke transfer from one room or suite to another.  Because cast and copper won’t melt, all that is required is a little fire wool around the pipe and then some fire caulk around any pipe that travels between floors or rooms.  With plastic, fire collars have to be installed on every pipe through a penetration, and these collars are quite expensive. On a commercial job, you may have hundreds of pipes passing through fire penetrations.

So for the most part, it has been both fun and interesting to work with plumbing materials that have been around for 12o years.

The auto blow down system required a valve and two couplings welded onto existing piping. I was pretty excited to have the opportunity to do this job as we do not have a lot of pipe work that needs to be done.

A section of the existing pipe needed to be cut out to mount the valve in place. The valve was fitted up and I checked it to make sure it was level and straight.Then I tacked it into place and welded it up.

For the couplings, I did the same thing; made sure they were straight and tacked them into place. For one of them it was difficult to get the proper angle to weld it on due to its location. So I had to weld the backside following nothing but a mirror I had someone hold up for me. This was quite challenging, however it was a great experience and fun to try for the first time.

After the welding was complete the system was pressurized and checked for leaks. All was well and that section of the unit was ready to be back up in service.

Each unit has a section called the spider; access to this location is from the main floor of the power house. Access to the spider is through aremovable cover on the other side of a small bolted-down door. Nuts are located on the bottom and they have been tacked on, as you are unable to reach your hand under to loosen or tighten the bolts. Over time, the nuts become stripped and need to be replaced. This is where I came in…

As you can see there is very little room to move around in the spider, which was not a major problem for me. I had to tape up a tarp to prevent sparks and debris from entering all areas of the spider as anything foreign could cause damage when the unit is back up and running.

I first needed to zip cut off all the nuts that had been tacked on, and I cleaned up the location with a grinding disc to get ready to tack on new ones.

To hold the nuts in place for welding, I bolted them on. This also prevented spatter from getting into the threads of the nuts.

After the welding was done I needed to slowly remove the tarp as to not throw around too much grinding dust and then use a shop vac to clean up any slack or metal shavings I left behind.

Here in Grand Rapids, we have our own water treatment facility. The water comes from a deep well and must be chlorinated and tested daily to ensure it is suitable for consumption. We also have two large commercial water softeners.

We sample the water at various points throughout the plant, such as the men’s washroom on the second floor. I need to take the necessary precautions to protect myself while in that room:

The most important test is done at the deep well itself. This is where the entire town’s water supply comes from.

The testing equipment is kept in a case. Here’s what the contents look like:

Two sample jars, two pouches of reagent, and the tester.

We start by filling a jar with sample water. In some sample areas, the water is constantly running. In others, we have to ensure it runs for atleast 5 minutes prior to testing. The jar must be rinsed thoroughly first before the reagent is added. The first jar we test has no reagent added. This is to zero the tester. Next, we add reagent. It turns the sample water pink. The amount of chlorine affects the strength of the colour.

Next we place the sample in the tester, and through the magic of electronics and lasers, it gives us a reading of the parts per million of chlorine content in the water sample.

The deep well results are recorded daily, and at the end of the month are sent to the government. We are required to maintain a certain level of chlorine in our drinking water to ensure there are no harmful bacteria present. If the level gets too low, we adjust the amount accordingly.

When unit 2 came down for repairs it was my job to insert lighting into the unit. Once lighting had been installed, I then had to map out the cavitation that existed on this unit and have an engineer come down and photograph each section. It was my job to assess the damage and decide whether to repair the damage or wait until the following year.

The damage was actually quite minor. So, because of the stator repairs that also needed to be done to this unit, there wasn’t enough time to haul our equipment into the unit and make the repairs in the time allotted to us. Therefore I decided to wait until next year to conduct the cavitation repairs to unit 2.

I began by repairing the cavitation on the runner. As usual I used the plasma arc gouger to do this. However, this time things were done a little differently with  the welding. Instead of using a wire feeder, I used an arc welder with stainless steel rods. This process is a lot slower, however there weren’t enough repairs to justify hauling in all of our equipment, and other aspects of the maintenance work required us to remove all of our equipment from the location. It was a lot easier to pull out only the stinger. In most cases requiring minor repairs or only a few spots to repair, we will choose to arc weld the repairs instead of wire feed them. I began repairing the damage on the runner, and then moved on to the liner.

These are photos of me arc welding the repairs on the turbine blades.

Here is a spot on the blade that had been gouged out and has a few stringers of weld already applied.

A completed repair

 .

Plasma gouging the liner.