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We Are Still in Emu Park, The Closest Place to Paradise on Earth

First off I have to apologise to our dear friend Libby in Adelaide. I know, Libs, I've become very slack in updating these pages. I'll try and do better in future. Let's start with the story of this caravan park's electricity system ...

A Shocking Situation

All the poor man was trying to do was wash up his dishes after dinner when he received an electric shock from, it seems, the tap water. Not a serious shock, but a definite tingle. And this wasn't the first time somebody had complained of a tingle from the water. The last person affected had been under a shower. Sue, the park manager, took the matter very seriously, as did the local council which owns the caravan park.

This caravan park has two parallel roads on the north side and three parallel roads on the south side. Each road has caravan sites along both sides and each site is supplied with mains power from one of many distribution posts strategically positioned for the purpose. All the distribution posts are connected to a network of underground cables, some of which are many years old. As this park has grown it evolved in a hotchpotch sort of way, as opposed to following an overall plan. Thus the location of the complete underground network was not to be found on any chart. The council sent out a team of electrical engineers with special sensing equipment which was capable of detecting cables buried about a metre below the surface. Paint marks were sprayed on the grass where further investigation was to follow.

A day or two later a large and very noisy machine arrived ...

Water Boring

... and used a high pressure water jet to churn a small area of soil into a slurry. Hovering just above the slurry was a vertical plastic pipe connected via a flexible hose to a cylindrical metal tank on the back of the truck. This tank was evacuated of air by a powerful vacuum pump - the source of the deafening noise. When the orange pipe was lowered into the slurry it sucked up everything including quite large stones and deposited everything in the tank. The operator then placed the water jet around the sides of the pipe, which hungrily sucked up the resulting slurry. And so it went on, deeper and deeper, the hole just a little wider than the orange pipe. If the water jet encountered an electric conduit, a cable or a water pipe, no damage would result. What they usually found was a course strip of concrete laid over an electric cable to protect it from picks and shovels should someone ever decide to dig there. It would, however, be no defence against a modern backhoe.

When the cable was found, the hole was widened around and below the concrete so that an electrician could lie on the grass with his arm down the hole and locate the cable or conduit under the concrete strip. They weren't forthcoming about what they were checking for but logically it would be to determine whether the cable was enclosed in a protective conduit, and perhaps to get some idea of its condition. One electrician reportedly suffered an electric shock. The holes were then back-filled with sand.

Decision Time

What to do, what to do? This park is a nice 'cash cow' for the council and was fully booked for the approaching peak (winter) season, this place being on the Tropic of Capricorn. Caravanners and tent campers need to hammer steel pegs into the ground to anchor guy ropes. Could the council risk doing nothing for the time being? No, of course not. Could the whole underground network be replaced with the park full of caravans? No, again. Could the council close the park until work was completed? That was one possibility. The other was to replicate the underground network of cables with temporary surface cables ...

Truck carrying generators

A forklift, lots of cables and connectors, numerous generators and fuel tanks descend on the park .

... and that is just what they did. Several matrices of heavy cables were laid out on the surface of the park, each matrix connected to a diesel generator. As soon as the generators were running, all caravans were disconnected from the old system and connected to the new. The underground cables were then isolated from the incoming power.

This arrangement worked well but with eight generators scattered around the park, regardless of the wind direction some caravans would always be in the path of diesel exhaust fumes. One or two people complained about the noise which was quite muted. Again the council acted quickly. The eight small generators were loaded onto trucks and removed.

Small Gens leave

The brightly-coloured generators on two trucks ready to depart. Some ladies were sad
as they had christened the machines with female names. Jenny, of course, was one.

The surface cables were re-arranged into just three matrices and three large generators were connected, one to each matrix. Furthermore, the three large generators were positioned outside the park boundaries and had a wall of straw bales built around them to muffle the sound. This eliminated the exhaust gas problems and much of the noise. It worked well after a few teething problems were resolved. This is how the park will be powered throughout the peak winter season.

Boss Lady Sue

Park Manager Susie Waterman sitting in a 'director's chair', overseeing the work.

One of the generators.

One of the three larger generators, ironically situated beneath the overhead power cables it usurped.

When the park occupancy reduces later in the year, work will commence on replacing the underground cabling. And that, Folks, is where we're at in early June 2016.

Winter and the tribulations of generator power.

It should be said at the outset that most of the problems that beset the temporary electrical system in the caravan park were caused by the safety devices doing just what they were designed to do - switching off the power when they detected a problem. To give some idea of the complexity of supplying over a hundred caravans with 240 volt mains power I am including a map showing the three generators and the caravan sites they powered. Each number represents a caravan or cabin.

Power Map.

Every one of the boxes on the map includes a residual current device (RCD), as does every modern caravan. The purpose of each RCD is to turn off the power immediately it senses 'earth leakage'. That earth leakage could be caused by any number of faults from a faulty electric kettle to somebody accidentally touching a live wire. The RCDs will 'trip' so fast that the chance of such a person being killed is hugely reduced. However, once an RCD in one of the upstream boxes trips, it cuts the power, not just to the caravans feeding from that box, but to every box 'down the line'. So if the caravan on Site 110 (top left on the map) has a problem with a toaster and trips the box, then sites 101 to 109 also lose power.

Now the fun starts. Imagine it's dark and raining. All you know is that one or more of those caravans on sites 101 to 110 is complaining that they have no power, but which one is causing the failure? If you're lucky someone will tell you that it happened when they switched on their toaster (for example) ... but more likely they won't. Then you start at end of the line furthest from the generator and work back, resetting any tripped devices as you go. (Sometimes more than one box will trip.) With all boxes reset there might still be no power, so the heavy fencing around the 'gennie' has to be opened and the RCD on the generator checked. If it has tripped the diesel engine has to be stopped, the switch pushed fully down into its 'OFF' position and then back up into the 'ON' position and the diesel restarted.

It may hold or it may trip again. If it trips the fault is still present so you disconnect the box nearest the gennie which isolates all the caravan sites along that line. You reset the gennie and start her up. This time she doesn't trip because the fault is in one of the isolated 'vans. Then all the loads have to be added back one at a time until the culprit is identified. Well, that's the theory; in practice the logical approach seldom seems to work but you eventually get there and return to your 'van, cold and soaking wet. At least the dark, cold and wet have one advantage; they keep away the well-meaning crowd of male 'experts' giving you gratuitous advice about what you should be doing - or whinging about the loss of power. On the other hand, handling wet equipment containing lethal voltages isn't a lot of fun. As the whole system is supplied with three phase power, the maximum voltage in every 'box' is 415 volts between any two phases. Quite enough to make your eyes water!

Initially, the electricians were called out for every power loss. However, the park's maintenance man and I soon grasped the concept and learned how to reset the boxes and generators to save a call-out. 'Stretch' (as he's known) worked during the day so was on hand but it was unreasonable to expect him to be on standby at night as well. The park manager, Susie, was fielding the night calls and summoning the electrician but she was already under a lot of stress and so I offered to take over so she could get a reasonable night's sleep. Actually there were not many calls at night, once the park was asleep, so it wasn't any great sacrifice. Not, that is, until the weekend of the great storm!
The Great Storm of 16th and 17th July 2016

The rain started on the Thursday night and forgot to stop. By Saturday the wind had increased to gale force and the rain was driving horizontally. Here we were with all this soaking electrical equipment lying in wet grass or mud. Naturally the number of failures went through the roof and Stretch and I were flat out and soaking wet most of the time.

Sites 58, 59 and 60 are situated in a hollow and were soon under water. The level was rising towards a stranded caravan on Site 56 and I was asked to tow it out as the occupants had no suitable vehicle. Well, why not? I couldn't get any wetter, could I?

In the rush, as the water rose, the caravan brake was left on but our Pajero still made easy work of it.

Froggie Hollow.

The site marker shows where Site 59 is ... below about a metre of water.

The drain as seen from the park entry. How it looks 99.9% of the time.

Drain.

The normally dry and grassy drain after the rain. It became a torrent.

As the weather continued to deteriorate, keeping the power flowing became almost impossible. As soon as we eliminated one fault, another would occur and trying to follow a logical diagnostic sequence just didn't work any longer. For example, one large, new motor home caused the generator to trip every time its power cable was connected. Despite its owner's protestations, there was no doubt that it was the culprit and we had no choice but leave it disconnected. A few hours later I tried again to connect it and everything was fine. Then the next day the fault returned and we had to disconnect again. We were concentrating on the owner's electrical appliances, one of which might have been faulty but we were looking in the wrong place.

Light dawned when I left the motor home and viewed it from a distance. There were two large vents on the side of the vehicle which allowed cooling air to circulate around the back of the fridge. One vent was vertically above the other so that heat from the rear of the fridge would generate a convection flow with cool air entering the lower vent and hot air exhausting from the upper one. But ... right between the two vents the builders had positioned the power inlet connector. Normally the vents would cope with falling rain but in these conditions the rain was being driven horizontally and directly into the vents which weren't designed to exclude it. It was entering the top vent and running down inside to the electrical input connector below, causing earth leakage and tripping the generator. Since it was hot behind the fridge it soon dried out until conditions changed again and more water entered.

Yes, you're right, that's all conjecture. But I'd put money on it ...

Motorhome

As this image shows, there must be better places to locate a 240 volt electrical connection.
Take note, Jayco.

Our Faithful Pajero has had his cataracts removed.

You might remember, we christened our Pajero 'Billy'. Why? Because we're nuts. Anyway, Billy is now 14 years old and with about 230,000 km on the clock, is still running beautifully.

Recently Pam and I had our cataracts removed and we can now see infinitely better. Just like our eyes, Billy's headlight lenses had become cloudy and dull and no longer allowed all the light through. We'd already tried polishing the 'glass' with a kit that is sold for the purpose. It worked for a while but was soon as bad as ever. Like our eyes, the new lights cost an arm and a leg!

Billy's Cataract

The picture below shows the left headlight before and after. The right light was similarly improved.

Jumping Forward to October . . .

Winter is over and spring is half gone. The lovely regulars, mainly from Victoria, have long since departed and Bell Park has quietened down. As expected, the north side of the park was cleared of caravans and totally fenced off. The generator and all the surface electrical equipment was removed and two excavators and a heap of equipment arrived. Three trenches were dug, each accepting three services; an electric cable, a water supply pipe and a drainage pipe (for caravan sullage). In due course the trenches were back-filled and all that remained to see were branches of the three services sticking up through the soil at intervals. To these are being connected new power distribution boxes, water taps and sullage drains. When complete, mains power and water will be reconnected and Bell Park North will return to normal.

Meanwhile, on the south side of the park are all the remaining caravans, still powered by two generators which seldom give trouble. In due course the caravans will be shifted north and Bell Park South will be fenced off and subjected to a complete sub soil renovation as per the north side. However, we will be leaving very soon and won't be back until around April 2017.






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