Near Intersection of I-35 & I-90 Southern Mn. | jbweston - 2/12/2011 22:32
....per section in the shut offs?
I don't know what the max allowable current draw is but relays can always be used to get around a limitation.
For example, I have used relays to work with high current clutches (your situation I assume) for some planter situations.
Relays can also be used to reverse the logic when necessary by utilizing the Common and N.C. contacts rather than the Common and N.O. contacts. Here are a couple of examples where I have used relays with planters.
Situation #1: Several years ago, Ag Leader had developed their Liquid Module for use with sprayers. This module did rate control and also with Autoswath could shut off sections of the sprayer. We had a customer who wanted to use this module to control sections on his planter that was equipped with the Tru-Count clutches but with the manual switchbox. Ag Leader had not yet developed the Clutch Control Module so the customer asked me to investigate utilizing his Liquid module from his sprayer for the planter. I was able to do this but the logic was reversed in the planter vs the sprayer. In the sprayer electricity is sent out when a section is to be ON, in the planter electricity needed to be sent out when a section is to be OFF or to stop planting. I was able to accomplish this idea by using a relay for each section and some other creative wiring.
Situation #2: A customer has a Kinze planter that has a drive on each end. The planter has clutches from the factory which were originally controlled by a switchbox in the tractor. The customer wanted to use Ag Leader's Clutch control module to shutoff the planter in "halves". The Clutch module seemed to have interference on this planter and wasn't working properly. I believe the original clutches might have had too much current draw or had some other problem. I was able to work around this problem by utilizing two high current relays that actually carried the load of cycling the clutches. The Clutch module was used to trigger these relays which is minor compared to the load of the clutches. The actual load of running the clutches was handled by the relays themselves which were wired directly to the tractor battery.
Relays are available in a wide variety of sizes and shapes. We have some high current weatherproof styles that we get from Waytek that we use in a variety of situations. Probably our most common use is to break the power in a high current demand situation to a high current device such as a Direct Chemical Injection pump. Here the relay is placed inline from the battery and is triggered by some source such as the vehicles keyswitch etc.
Edited by tedbear 2/13/2011 16:32
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Field IQ. What is max allowable current draw....
