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mathcounts
New Member
United States
1 Posts |
 Posted - 02/12/2007 : 11:56:10 AM
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I'm a math teacher in COLD North Idaho doing a break-even analysis for installing timers on our large district fleet of school buses. Currently the drivers plug the buses in right when they get to their parking places after delivering kids. This is about 5:00 in the afternoon. I want to propose installing timers for the engine block heaters. Our director of transportation tells me that the heaters are both 1,000 and 1,500 watts. I am wondering if any of you members here know a good model of timer and where to purchase them that you could recommend which would allow multiple bus plug in (currently they have two buses per outlet).
Any help apreciated! I know our district could save a great deal on electricity use. Thanks in advance for any help or comments. |
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torque
Advanced Member
Canada
358 Posts |
Posted - 02/12/2007 : 4:16:11 PM
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1500 watts, is about 12.5 amps. Are you sure your 2 busses per outlet are not split outlets?
I am not sure about the USA, but in Canada we are only alowed 15 amps per outlet.
You might also want to check with a local electrician for their advice,
If going with a timer, I would want something with a battery backup for the time, nothing worse than the power going out, and tiem trown off :)
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IBTMech
Top Member
USA
973 Posts |
Posted - 02/12/2007 : 6:06:31 PM
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I will check on the brand name of the timer we use. We have it set to come on at 3:30 AM for 6:30 start up.
All of our buses have a 1250 watt heater with their own outlet and GFCI. |
If it doesn't fit, FORCE it.
If it breaks, well, it needed replacing anyway.
Pullin' wrenches for 45 years. |
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Craig Thoricht
Senior Member
USA
177 Posts |
Posted - 02/13/2007 : 01:33:31 AM
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We put timers on our outlets several years ago. Our electrician used Intermatic timers from W W Grainger. They are 24 hour timers.Any larger size industrial supply should be able to supply those for you.
If you haven't installed them by now you should know that we installed the timers in january. We are in northeast Ohio and the timers paid for themselves in savings on electricity in the first month.
We have them set so that they are on 3 hours before they start in the morning. That is plenty of time for the engine to warm up.
You will have to install these according to your local electrical codes and probably be done by a licensed electrician. The electrician will be able to tell you the mechanics of the installation.
Regards-
Craig |
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flyboy
Senior Member
USA
147 Posts |
Posted - 02/13/2007 : 04:46:17 AM
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| We have the electric supply for the bus block heaters utilizing both a timer and a thermostatic switch. Our heaters are set to go on below 40degF and at 3:00 am. the timer stays on all day and then is set to shut down at 2:00 pm. This system was installed when the facility was built. We also used the Intermatic portable time switch for buses remotely stored. |
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bbird66
Top Member
USA
881 Posts |
Posted - 02/13/2007 : 08:13:29 AM
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I forbid the use of them, Most of my drivers are in the country and didnt understand the use of a industrial size timer anyway and could not figure out am/pm thing (After showing them how) and some were going off at odd times ect. I threw them all out and now I sleep well when the sub zero weather hits!. I dont think you save that much and besides they dont plug in unless we hit 15 to 20 degree range or lower. If you are pointed into a very cold sub zero wind and expect that heater to warm up say a 466 thats cold soaked over a weekend in three hours, Forget it.
If and when you do go that route make sure when they click on, those timers can handle the initial surge or you will be curseing them. When timers were used here they were Dayton all weather timers, Our drivers that are in the country are compensated 35$ a year for electricity use. Some neighboring districts pay a little more up to 50$. |
Were gonna miss you "Brent"..Good luck in "Heidi land"
"I know you miss the Wainwrights Bobby, but they were weak and stupid people...and that's why we have wolves and other large predators" .. The Far Side
"On a two hour delay when will my child be picked up??"
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IBTMech
Top Member
USA
973 Posts |
Posted - 02/13/2007 : 5:43:40 PM
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Intermatic is the brand of timer we use. A thermostatic switch sounds like a good idea and I will bring this up to the bus super.
For what it's worth, a driver recently complained that his bus was starting hard ('04 IH/DT466). The temp that morning was -3 F and it started with no assistance....... not very happily, but it started. The block heater was NFG. |
If it doesn't fit, FORCE it.
If it breaks, well, it needed replacing anyway.
Pullin' wrenches for 45 years. |
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Bus 29
Active Member
USA
47 Posts |
Posted - 02/18/2007 : 6:11:02 PM
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| We are in the same boat as bbird66 we are NOT allow to use timers of any kind. and with good reason 3 hours is not enough time if it is really cold out. and yes we have had drivers use them and there buses did not start the next morning. |
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ModMech
Top Member
USA
948 Posts |
Posted - 02/24/2007 : 7:06:42 PM
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mathcounts,
Comming from the enginereing side of this, there is no "silver bullit" answer that convers all potential cenarios.
Our fleet of gas/diesel/LP busses had timers for the block heater circuits. The heater circuits ranged from 650W to 1500W, so balancing the draws was a BIG problem.
Our timers were located in a seperate service panel along with the relays they controlled next to the circuit breaker panel for the block heaters. ALL our switching was done inside at a central location. IMO, if you are using timers, this is the ONLY secure way.
Now we get into the when to turn them on discussion, or arguement if you were me vs the owner. Many people feel there is a magic time to turn on the BHs, nothing could be further from the truth. At 0*F with with a fleet of T444Es you can get buy with 5am. Under the same conditions with a fleet of 8.2L NA engines, and 3am is necessary. We are assuming moderate wind chills as well.
There were many times when I drove back to work and tripped the timers on at 11PM because I KNEW that 3am was not going to cut it at -24*F with 20 MPH winds. Three hours does not get it under those conditions in a mixed fleet.
If I had to choose one time, I would turn them on a 2am for a mixed fleet, possibally later if you had all well starting units with Glow Plugs and three batteries in a moderate winter climate. |
If you want customer service, you NEED an International! |
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IBTMech
Top Member
USA
973 Posts |
Posted - 02/24/2007 : 9:03:14 PM
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I feel fortunate that our entire bus fleet is comprised of all IH DT466s and one DT360.
When the temps are expected to be below - 10 we bypass the timer and leave the block heaters on all night.
It works for us. |
If it doesn't fit, FORCE it.
If it breaks, well, it needed replacing anyway.
Pullin' wrenches for 45 years. |
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Wolf0r
Top Member
USA
2181 Posts |
Posted - 03/06/2007 : 12:45:08 PM
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| All it would take is for the bus builder to install and on-board timer. The multi-plex or PCM could be used to control the heater circut. An ambient temp switch would work. |
“The good thing about science is that it's true whether or not you believe in it.”
Neil deGrasse Tyson |
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Engine block heater timers
