Monitoring Furnace Glow Bars

5 comments

Rate

krypton1592 Participant Join Date: Nov 2006 Posts: 2	Monitoring Furnace Glow Bars 11/29/2006 6:29 PM
	I am doing a project on a furnace and one of the things i want to do is to be able to monitor the glow bars incase they break there are 8 glow bars that are pulling about 60 amps at 240 volts. and thay are paired in 2s so i know i can read a voltage drop across the two . but i need a Convertor with at lest 8 to 12 inputs and outputs that can convert the 240 volts AC to 120 volts AC or Convert it to low Voltage DC with a limited amount of space . then the output of the Convertor will go to an AllenBradly PLC. Thanks
	Register to Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

nutwood Power-User Join Date: Jan 2006 Location: Australia Posts: 269 Good Answers: 1	#1 Re: Monitoring Furnace Glow Bars 12/01/2006 1:11 AM
	Can't you put current clamp transducers on the supply cables and monitor the current draw? You should have no problem getting a transducer to read 60 or 120 amps AC and give you a 4 - 20ma signal for your PLC __________________ An engineer is a man who can do for five bob what any bloody fool can do for a quid (Neville Shute)
	Register to Reply

Cornstoves Power-User Join Date: Dec 2005 Posts: 200 Good Answers: 8	#2 Re: Monitoring Furnace Glow Bars 12/01/2006 3:03 AM
	Standard practice is to use a safe, reliable, low cost instrument transmitter or hockey puck for each input/output (I/O) to the AB PLC. AB PLC powers each transmitter with say 24 VDC. Transmitter Output signal is 4-20madc. Zero output represents circuit failure. 20 madc represents max signal 4 madc represents min signal. Calibration is users choice. AB PLC can be programmed to read out current, voltage, watts for each circuit, all circuits combined, or any combination of interest. __________________ Corn Stoves
	Register to Reply

krypton1592 Participant Join Date: Nov 2006 Posts: 2	#4 In reply to #2 Re: Monitoring Furnace Glow Bars 12/01/2006 7:56 PM
	How much Heat can the transmitters take. where i would have to mount them is about 1000 degrees C Thanks for the help
	Register to Reply

Cornstoves Power-User Join Date: Dec 2005 Posts: 200 Good Answers: 8	#5 In reply to #4 Re: Monitoring Furnace Glow Bars 12/02/2006 3:33 AM
	Are there any other surprises in addition to the ambient temp of 1000 deg C? Mount the transmitters at the power source. If you insist for no good reason to mount electronic devices inside a boiler, first check with your psychologists, and secondly use exair (see www.exair.com) coolers. __________________ Corn Stoves
	Register to Reply

Anonymous Poster	#3 Re: Monitoring Furnace Glow Bars 12/01/2006 5:26 PM
	How about indicating fuses across the bars. An open bar will trip the fuse and provide failure indication via a switch from the fuse holder to your control circuit. It's old tech, but it works, - cheap too.
	Register to Reply

Copy to Clipboard

Anonymous Poster (1); Cornstoves (2); krypton1592 (1); nutwood (1)

You might be interested in: Furnace Controllers, Heating Furnaces, Igniters

	Got Something to Say?
	Ask a Question Start a Discussion

	Aerospace
	BioMech & BioMed
	Chemical & Material Science
	Civil Engineering
	Communications & Electronics
	Education and Engineering Careers
	Electrical Engineering
	General Discussion
	Instrumentation
	Manufacturing
	Mechanical Engineering
	New Technologies & Research
	Software & Programming
	Sustainable Engineering
	Transportation

	Site Directories
	Forum Directory Blog Directory User Group Directory RSS Feeds CR4 Rules of Conduct CR4 FAQ Site Glossary Who's Online (65 right now) Show Members