need help trouble shooting a hunter acc 2 wire

tlawn86

LawnSite Member
Location
Katy
One of my location have a hunter acc 2 wire. nothing works. and the error code i get is "overcurrent" or "no comm" Does any one have any ideas. here what ive done first i went threw with my wire locater to check for broken wires and located all the valves. i also replace every connections with the 2 wires running to all the decoders. also there are 22 stations.

Todd
 
OP
T

tlawn86

LawnSite Member
Location
Katy
One of my location have a hunter acc 2 wire. nothing works. and the error code i get is "overcurrent" or "no comm" Does any one have any ideas. here what ive done first i went threw with my wire locater to check for broken wires and located all the valves. i also replace every connections with the 2 wires running to all the decoders. also there are 22 stations.

Todd
i for got to also say i called hunter tech support to get specs to check the ACC controller
 

HunterTekGeek

LawnSite Senior Member
Location
San Marcos, CA
Hi tlawn86 - I work for Hunter and don't jump in here often, so I hope this is okay. First, I invite you to call Tech Service at 800-733-2823 to help get this resolved. It helps us both when you are in front of the controller when we speak.

"Overcurrent" means the controller has gone into self-protect mode when the milliamp draw goes beyond 2,200 mA. What causes this? Broken or skinned wires making earth contact (the 2-wire path) will draw excessive amperage. If the 2-wire path is properly grounded, check the decoder(s) that are connected to a ground rod or plate. All Hunter ICD decoders have a single copper grounding wire. That is the "wire" that would be connected to earth ground. If the decoder(s) look damaged from surge, disconnect them from the 2-wire path and check the amperage at the controller. This is done by going to "Advanced Features", "Decoder Functions", "Check ADM Current". The ACC has an on-board amp-meter in the face pack display for firmware versions beyond 4.00. A 3.00 face pack does not have this feature but can be flash updated (by you!) to the current version which is 5.01.02 (see web site for firmware updates and instructions at: http://www.hunterindustries.com/sites/default/files/ACC_Flash_Update_Instructions.pdf).

To check the version turn the dial to "Advanced Features" then press and hold the blue INFORMATION button. The firmware revision and station size/count will be displayed.

Each decoder draws 3.5 to 4.0 milliamps. Round it up to 5 to keep the math simple. Example: 50 decoders x 5 mA = 250 mA. Just like 50 rotors x 5 GPM = 250 GPM. The amp draw is predictable and useful.
If the milliamp reading is still high, try this. Go to the first decoder on the 2-wire path. Disconnect the "downstream" wires. Keep that single decoder wired up and re-check the milliamps at the ACC. If the reading drops way down to <30 mA, you just proved you have a wire path problem and not a clock problem.

There are high tech ways to troubleshoot from here. The LawnSite guys are pros at this and I expect you will get some seriously good responses regarding clamp-meters and ground fault locators. A simple method is to start halfway down the wire path and open the splice. This isolates 50% of the path. If the amps go down to normal the problem is further downstream. Reconnect the splice and go another 50% of the distance downstream and again break the splice in the valve box. Lather, rinse, and repeat. Check the milliamps at the controller. The idea is to get to the general area and look for any recent digging, gophers, new tree stakes, anything that would cut or disturb the wire path. The highest incidence of problems come directly from bad splices but you said you replaced/repaired each connection. Use 3M DBYR-6.

Bad decoders are rare, but can cause overcurrents. A quick way to see if a wire path is in good shape or not is to take a resistance reading. You will need a good voltmeter, not a cheapie. Disconnect the wires from the controller. We are looking for 600,000 ohms or higher. This indicates the insulation and splices have good integrity. If you read 25 ohms, the normal reading for many solenoids, you have a major problem with the wire path, surge arrestor(s), or possibly a decoder. Again, 600K+ is great. 300K is reason for concern. Zero to 50K will cause an overcurrent.

If you haven't glazed over by now I can tell you that a "COM FAULT" alarm means that the ACC cannot communicate with the decoder(s). Or you have two decoders with the same address. Or that address just physically does not exist on the 2-wire path. The presence of your "Overcurrent" alarm can contribute to the "COM" error too. When current flows to ground the addressing signal from the controller gets garbled and doesn't reach the decoder(s) in good shape. The ACC Decoder controller uses 2-way communication. It relies on the decoder(s) ability to recognize and constantly acknowledge the signal when the station is running.

If you have multiple wire paths connected to the controller it gets a little easier. Disconnect all but one path (2 wires, red and blue) and see if that path is good or bad. If you have only one pair of wires attached to the ADM (ACC Decoder Module) terminal strip but know that the path splits in different directions away from the controller you should isolate the paths there by breaking the splices and work with one wire path at a time.

Sorry. Long reply. I teach a 2-day decoder troubleshooting class. There is more information about this than space will allow. Feel free to ask for Rod if you call Hunter again. Learn how to read the millamps at the controller. Make sure you know where the wire path goes and where you can isolate different legs or runs. Look for other posts to follow from the LawnSite contractors. They have great tools and techniques for decoder system troubleshooting. I hope this helped. Good luck!
 

1idejim

LawnSite Fanatic
if more reps reacted to product concerns the way you do Rod i believe they would received much better on this or any forum.

not once in your post did you use the op's issue for an opportunity to fly the corporate colors, instead you gave product specific advice.

you are a perfect example for any reps or sponsors that intend to participate on any professional forum.

reps and sponsors could learn a lot from your posts, once a product has been introduced quit selling and help when help is needed.
 

Kiril

LawnSite Fanatic
Location
District 9 CA
if more reps reacted to product concerns the way you do Rod i believe they would received much better on this or any forum.

not once in your post did you use the op's issue for an opportunity to fly the corporate colors, instead you gave product specific advice.

you are a perfect example for any reps or sponsors that intend to participate on any professional forum.

reps and sponsors could learn a lot from your posts, once a product has been introduced quit selling and help when help is needed.
Couldn't agree more. :clapping:
 
OP
T

tlawn86

LawnSite Member
Location
Katy
Rod your a big help.. when i called hunter support last thursday the rep i talked to was just reading a book and didnt know a clue what i was talking about almost. ill ask for you next time you really know your stuff.. :) im going to the location this afternoon to do more testing with the info you gave me.

Also do you ever do 2 wire classes in texas?
 

Wet_Boots

LawnSite Fanatic
Location
metro NYC
If you are going to maintain 2-wire systems, you want to have a clamp-around "leakage meter" that can read the milliamp currents drawn by the decoders
 

HunterTekGeek

LawnSite Senior Member
Location
San Marcos, CA
Thanks to all for the kind words. Sprinkus, nice job on providing the Decoder Troubleshooting Guide. I think it isn't posted online because it needs updating. I will check on it. The Decoder Design Guide isn't super great for troubleshooting but it does help clarify things graphically: http://www.hunterindustries.com/sites/default/files/DG_DecoderDesignGuide_dom.pdf

Wet Boots is right. Get a clampmeter. Armada has a good one: http://www.armadatech.com/Pro93 (Remember, it has to read milliamps.)

How to use a clamp-meter to troubleshoot:
1. Disconnect the 2-wire path(s) from the controller.
2. Sounds weird, but you need a 24 VAC transformer. 1.5 Amp, fused, with alligator clips, with the primary wired to a pigtail. I have better luck using a 24 VAC signal. The clamp-meter will give accurate readings. Remember, the native current on ACC is 1.2 Hz at 35 volts AC. The voltage bounces at 1.2 Hz and is sort of unreadable.
3. Connect the transformer leads to ONE 2-wire path.
4. Plug the transformer in. I carry 200 feet of extension cords. Find an outlet.
5. If an outlet is not available I use a high output inverter that connects to my truck battery. It has two 120 VAC outlets.
6. Hunter ICD Decoders draw 8.5 to 10 milliamps at 24 VAC. This is crucial to know. Earlier I said each decoder drew 3.5 to 4 mA. Yes, but at the native 35 VAC & 1.2 Hz.
7. Example - 22 decoders x 10 mA = 220 mA @ 24 VAC
8. Clamp on to ONE wire only. Take a reading. Then clamp on the other wire. When things work right you should read close to 220 mA on each wire at your site.

9. If you read 500 mA and only have 22 decoders, there is a hot spot(s) downstream.
10. Example: Football field. 100 rotors. One 10 GPM rotor every yard = 1,000 GPM. Yep, stupid. Try to go with it. If you had a flow meter on the goal line you will see 1,000 GPM. If a flow meter is installed at the 50 yard line you get 500 GPM because you can only read the flow past that point, heading to the other goal line.

Same for amperage. 1,000 mA at the clock. 500 mA at the 50 yard line. 200 mA at the far 20 yard line. Okay?

In your case your baseline amperage SHOULD BE 220 mA (remember) at 24 VAC. It should only be around 88 mA when the path is connect to the clock. Sorry, confusing but this is important to remember.

Let's say you read 1,000 mA with the 24 Volt transformer setup at the ACC. Start walking down the wire path and take a reading on the 2-wire path in the valve boxes. Read the blue, then the red heavy gauge wires, not the red/blue decoder leads. If still HIGH, keep walking. When the clamp-meter reading drops way off, say below 220 mA. Stop. The problem is behind you. You had 1,000 mA one hundred feet back and 50 mA, or even zero, where you're standing now. The problem is between Point A and B. Make sense?

11. Just like a broken pipe, electrical current will flow to ground where there is a skinned wire, bad splice, etc. The beauty of the clamp-meter method is that you don't have to break splices to get a reading.

12. It sounds complicated but it is pretty easy once you do it.

13. Super Important! Hunter decoder milliamp draw (specs) are different than other manufacturers. The 3.5 and 8.5 mA (@ 1.2 versus 60 Hz) draw for Hunter does not hold up for Rain Bird and Tucor. Test them yourself or see if the LawnSite guys have these numbers. Just like solenoids, the amp draw differs from manufacturer to manufacturer.

14. Last tip: Carry extra decoder wire or even plain 14 gauge UF wire with you. If you find a suspicious section of wire you can bypass it as a temporary fix. Doing that, if the milliamps drop to normal at the ACC or the clamp-meter you know you are on the right track.

15. Next, save up for a ground fault locator and be amazed.

Thanks and good luck!
 

Sprinkus

LawnSite Silver Member
Location
San Antonio, TX
reps and sponsors could learn a lot from your posts, once a product has been introduced quit selling and help when help is needed.
That would require intelligence, integrity, and insanity. Something that too many people lack these days.

And the above post from Rod, what a great name, is saved for future reference!
 
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