luggsey Posted January 18, 2007 Share Posted January 18, 2007 Nope, never did much 24vdc with Came. Ended up switching to Nice equipment for that, and very good it is too, especially the auto set up sequence. The fact as well its so good at obstruction detection you can even (don't please but i did test this) not even use safety beams in a pedestrian environment. I like the Came "pick your current" selection on the transformer, pick just enough to close the gate and if it touches anything it reverses the gate. Wouldnt even mark your bumper! The 24 volt stuff is for 100% duty cycle, don't know why that is?? It's well made kit though else why would I install on my own gates! ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2007 Share Posted January 26, 2007 I like the Came "pick your current" selection on the transformer, pick just enough to close the gate and if it touches anything it reverses the gate. Wouldnt even mark your bumper! The 24 volt stuff is for 100% duty cycle, don't know why that is?? It's well made kit though else why would I install on my own gates! Forgot about this, the 24vdc systems dont overheat as much as 240vac so can be higher duty rated. For example a ATI 240 vac arm will cycle about 12 times then the thermal cut outs will engage. Where as the 24vdc wont. Link to comment Share on other sites More sharing options...
luggsey Posted January 26, 2007 Share Posted January 26, 2007 Forgot about this, the 24vdc systems dont overheat as much as 240vac so can be higher duty rated. For example a ATI 240 vac arm will cycle about 12 times then the thermal cut outs will engage. Where as the 24vdc wont. Funny thing is low voltage high torque motors normally heat up quicker then their mains voltage brothers? Must be summit else in it? ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2007 Share Posted January 26, 2007 Funny thing is low voltage high torque motors normally heat up quicker then their mains voltage brothers?Must be summit else in it? Nope experienced it 1st hand a set of gates kept failing at peak times when ac. After i fitted 24v the problem stopped. Ring Heather at Nice she`ll explain it all, or Trevor at Came but the Nottingham head office not the trade centre. Link to comment Share on other sites More sharing options...
luggsey Posted January 26, 2007 Share Posted January 26, 2007 Nope experienced it 1st hand a set of gates kept failing at peak times when ac. After i fitted 24v the problem stopped. Ring Heather at Nice she`ll explain it all, or Trevor at Came but the Nottingham head office not the trade centre. Yes, I'm not doubting it as a fact, I did say it! Just observing that low voltage generally means more heat no? ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2007 Share Posted January 26, 2007 Yes, I'm not doubting it as a fact, I did say it! Just observing that low voltage generally means more heat no? Its the heat generated at the motor windings thats the problem. this might help just found it DC drives are more energy-efficient. AC drives have two stages of power conversion (AC to DC then DC to AC). DC drives have one stage (AC to DC). Each stage has energy losses, in the form of heat generated in the drive. More heat is generated during switching (switching losses). The higher the switching frequency, the more the losses. If braking is required, the regeneration available in most DC drives will increase efficiency further beyond the DB resistors used on most AC drives With their additional stages and higher switching frequencies, AC drives generate more heat than DC, and are less efficient. Hope that helps Link to comment Share on other sites More sharing options...
luggsey Posted January 26, 2007 Share Posted January 26, 2007 Its the heat generated at the motor windings thats the problem.this might help just found it DC drives are more energy-efficient. AC drives have two stages of power conversion (AC to DC then DC to AC). DC drives have one stage (AC to DC). Each stage has energy losses, in the form of heat generated in the drive. More heat is generated during switching (switching losses). The higher the switching frequency, the more the losses. If braking is required, the regeneration available in most DC drives will increase efficiency further beyond the DB resistors used on most AC drives With their additional stages and higher switching frequencies, AC drives generate more heat than DC, and are less efficient. Hope that helps I was confused before now I'm more confused! Our electricial grid used to be DC many moons ago and I thought the reason for going to AC was for motors to work better (Using phases lagging each other) On a single phase motor the phases as it were are created using capacitors to put the current 120 degrees apart so I'm still confused as to why lower voltage, and by default more current can produce less heat? That's going to bug me untill I find the answer or I understand the one you found! AARRGGGHHHH! ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
amateurandy Posted January 26, 2007 Share Posted January 26, 2007 Our electricial grid used to be DC many moons ago and I thought the reason for going to AC was for motors to work better No, it was to reduce losses in the transmission grid. Link to comment Share on other sites More sharing options...
luggsey Posted January 26, 2007 Share Posted January 26, 2007 No, it was to reduce losses in the transmission grid. Yes you are right about transmission loss, AC is far better, got the grey matter working now! It was the discovery of the induction motor that led to this, that's where I got the idea from (Tesla rings a bell??). Just had a thought that DC motors have "much" higher starting torque then AC motors so that's a reason to use them in a low speed high torque duty rated 100% installation, possibly the AC version makes more heat on each "start" cycle but as I said would possibly run cooler over time. I really enjoy bouncing ideas around like this, it's an enjoyable way to learn! Better then trying to remember which menu a setting can be found in.... ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2007 Share Posted January 26, 2007 Yes you are right about transmission loss, AC is far better, got the grey matter working now! It was the discovery of the induction motor that led to this, that's where I got the idea from (Tesla rings a bell??). Just had a thought that DC motors have "much" higher starting torque then AC motors so that's a reason to use them in a low speed high torque duty rated 100% installation, possibly the AC version makes more heat on each "start" cycle but as I said would possibly run cooler over time. I really enjoy bouncing ideas around like this, it's an enjoyable way to learn! Better then trying to remember which menu a setting can be found in.... Nice one, got me to thinking as well. Far more fun than assuming. Link to comment Share on other sites More sharing options...
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