Posted by Tarzan on June 14, 2001 at 06:32:00:
In Reply to: Re: Second McDonnel 157!Thanks!TARZAN- One more question. posted by BoilingMan on June 13, 2001 at 05:12:50:
: : : Having a second McDonnel Level control, is it mandatory
: : : or matter of choice! And what it sposed to do?
: : You need two LWCO's installed (one of which must be manual reset) if you operate a power boiler that is not constantly attended. Louisiana state law goes on to describe that the boiler must have an audible alarm and that the boiler must be checked at least every 2 hours....Why you ask?
: Because head mechanism on the second MDM ruptured.
: And now I'm in guess to replace it or eliminate it, factory manual does not have any info about it.
: Should it be of float type or solid state with a probe and so on.
: Could U tell me pls where to get all that official regulations, You was talking about?
: I've got the last issue of State marshal regulations, but there is not a word about that.
: Thanks a lot!
My Soviet comrad,
No, you don't want to eliminate it! One of the LWCO's contains two switches....one switch controls your feed pump and the other is the actual LWCO switch....I'm sure you have the model 157 float type M&M's, one on each side of your F/T boiler....Just one of the LWCO's will contain two switches, the other LWCO contains only one....pull the top cover and you will see either one or two mercury bulbs...If it contains only one bulb, that unit should be the manual reset type...It will have a push button that extends thru the cover for reset...Either Head unit is readily availabe and ya otta have a spare anyway....While you are in there look close at the wires feeding into the head unit....they tend to get so hot that the insulation cracks and falls off....if so, replace the wire with hi-temp rated strands...Hell, I'll just stop by there today on my way home and we can exchange insults while I look at your boiler....I may have the parts you need layin around...
The requirement is stated in the rule book...look in the back under "Attendance of power boilers"
Low water is the leading cause of boiler failure and failure of the LWCO is the leading cause of a low water condition...so never remove an extra LWCO device.