day tank for oil furnaces

ddenny

recently installed a day tank in a factory (first time I did one). think I got all the copper lines correct. the main tank is an above ground 275. I installed 2 copper lines (supply and return) from the tank to the motor/ pump assembly which of course sits indoors on a platform about 12 feet above the 275 tank.2 copper lines from the motor pump assembly go up about 3 feet and run along the wall about 30 feet to the day tank. the day tank feeds 3 "hanging coffin" furnaces which are in different parts of the factory. a single line feeds each individual furnace. one furnace is just a few feet from the day tank and about 3 feet higher than the day tank. another is also about 3 feet higher than the day tank but 40 feet away. the third furnace is about 30 feet from the day tank and slightly lower. like I said each furnace is fed by it's own 3/8 inch line. with only a 3 foot lift above the tank I figured I did'nt need a 2 pipe supply and return system to the furnaces. on the day tank itself is what looks like an air vent on top but someone said it was a vacuum breaker. and on the right side is I guess a pressure switch which I wired up to tell the pump/motor assembly to go on and off as needed.
the first time I turned it on it seemed to work fine. but then I got a call from the guy saying it was cycling which it was every few seconds. so I fiddled with the pressure switch and it seemed to stop. but I got a call back again and it was doing the same thing. the guy also told me he turns the heat down low on friday before leaving then has to bleed the lines at the furnaces on monday. at this point I jumped out the pressure switch and I have'nt got a call back on it but would still like it to work properly. any ideas what I can check for?

Firedragon_4

I guess my only question is

why put the booster 12' above the tank? The lower it is the lower the vacuum and the pump only works to overcome vacuum.

After that it's easy to remember that vacuum is work for a pump, pressure it just does its thing! Remember over 10" of vacuum and oil starts to hydrogenate or split apart.

Absolute vacuum is under 30", FACT! You can pump oil under pressure to China if you want and they make gausges to 10,000 psi, so...........

I'd drop the pump, recheck the fittings and I know you'll find it and fix it.

clammy

jump out pressure?

By jumping out the pressure switch doesn,t the lift pump run constant and if so is there a over flow back to the tank ?You could also have done away with the day tank made a pressure system with a relay to pull the lift pump on and pressure switches to bring the pump on i've done a few that way no promblems to bad you can't get N E hite day tanks any more they where very nice .Have you given any thought to tiger loops on the burners

ddenny

day tank problem

hello firedragon
thanks for your answer.
I put the pump on a platform because it was already there and people are working beneath it. if I havee to I'll find a place to put it on ground level.
what still confuses me is why the pressure switch was cycling the motor on and off as if it was pushing against some pressure. maybe sucking in through a fitting or filter.

Firedragon_4

If your vacuum is

unstable it will affect your pressure and the switch will go nuts.

Next time use a switch with more play in it, I love using Ford brakelight switches, GM or Mopar works too :-)