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User Guide | Danfoss troubleshooting guide for supermarket electronics

© Danfoss | Climate Solutions | 2022.02

BC337731384771en-000301 | 3

1. AK-SM 800A

Compressors not coming on with high suction

1.  Check status screen of rack to see if any warnings are listed (i.e. phase loss, high discharge pressure, 

oil fail, etc)

a.  For high discharge pressure, check settings tab to confirm cutin/cutout values for “Disch 

pressure safety” are appropriate (cutout should be higher than cutin)

b.  For phase loss, oil fail, see if the device sending Danfoss a signal is tripped (i.e. phase loss 

monitor, oil sensor). If so, that device needs to be investigated. 

c.  If the device is not tripped, check wiring and polarity in program (under Addresses on-off inputs 

tab) to ensure proper config (i.e open/closed/voltage/no voltage). 

2.  If no warnings are listed, check staging pattern of controller (auto/manual) under Settings

a.  If set to manual, # of steps should be greater than 0, and individual steps should show 

compressors selected with capacity increases from one step to the next.

b.  Reset the controller after reviewing this section (even if no changes made). Staging pattern 

changes do not take effect until after a reset. 

3.  Check Address section to ensure relay address for compressor still exists, polarity correct.
4.  Under status screen for rack, select “Service” and confirm no manual overrides on compressors

IO Offline

1.  Verify Power to modules, Complete rescan

a.  Power supply to comm modules should be 24 V AC/DC

2.  Verify ‘Channel Lonworks’ enabled on Network Nodes screen

a.  If not, enable and rescan afterwards

3.  Verify term resistor switch position at AK-SM 800 is correct

a.  If 1 loop from plug, switch = ‘On’ position
b.  If 2 loops from plug, switch = ‘Off’ position

4.  Verify EOL resistor in place at end of loop(s)

a.  120 Ω resistor or term switch in On position 
b.  If term switches exist on modules in middle of loop, need to be in Off position

5.  Verify comm module addresses via rotary switches
6.  Verify that there are no hairline shorts on the comm loop terminal
7.  Verify comm loop is run as point-to-point daisy chain (no branches, etc)
8.  Verify comm cable type 

a.  EIA RS 485 (max. 4000’) for Modbus and LON RS485 devices
b.  120 Ω impedance, 42 – 75.5 pF/m capacitance, typically 22-24 AWG

9.  Isolate loop in sections, rescan

a.  Identifies where comm problem may be introduced

Case Controller ‘Mismatch’ Issue

1.  Go to Network Nodes 

→ 

Scan Status 

 Controllers

a.  Locate address in list
b.  Note controller version, part #, type shown

2.  Go to Configuration 

 Control 

 Refrigeration 

 Circuits Type

a.  Confirm type matches info from #1 above
b.  If not, change selection in list to proper choice
c.  Rescan after updating

3.  Common mistakes

a.  For AK-CC 550A, parameter o61 not set to match program.

i.  Typically o61=2 for most setups

4. Recommendations

a.  Use ‘Show only scanned devices’ option at top of Circuits screen to limit choices
b.  If correct choice is missing from list, update system manager to latest version of firmware

AK-SM 800A Stuck on ‘Verifying Nodes’

1.  Go to Network Nodes, verify only channels being used are enabled

a.  Disable any channels not being used
b.  Reset AK-SM 800A

Содержание AK-SM 800A

Страница 1: ...User Guide Danfoss troubleshooting guide for supermarket electronics www danfoss com...

Страница 2: ...C 550A to AK SM 800 7 Dual Temp Setup 7 4 AK CC 750 7 Replacing AK CC 750 7 5 AK XM Modules 7 AKS Temp Sensor not Reading on IO Module 7 AK XM 103A module not coming online 7 Relay will not respond to...

Страница 3: ...should be 24 V AC DC 2 Verify Channel Lonworks enabled on Network Nodes screen a If not enable and rescan afterwards 3 Verify term resistor switch position at AK SM 800 is correct a If 1 loop from pl...

Страница 4: ...4 Replace AK SM 800 IO Offline 1 Verify Power to modules Complete rescan a Power supply to comm modules should be 24 V AC DC 2 Verify Channel Lonworks enabled on Network Nodes screen a If not enable...

Страница 5: ...ue address 3 Verify connection from AK SM 800 to switch and switch to network a Could be the issue with the cable b Power cycle network switch router or cell modem 4 Reset AK SM 800 a Make sure to res...

Страница 6: ...dc c Measure voltage across terminals 31 32 Should be in range of 0 5 4 5Vdc d Verify transducer type Label of transducer should say AKS32R HFC or AKS 2050 CO2 S3 Error E25 1 If no return air s3 senso...

Страница 7: ...e or loose connection between module and probe b If reading closed likely a short in cable between module and probe c If reading expected resistance compare to temp ohm chart for PT1000 move sensor to...

Страница 8: ...ion IO Offline 1 Verify Power to modules Complete rescan 2 Verify Channel Lonworks enabled on Network Nodes screen a If not update and rescan afterwards 3 Verify EOL resistor in place at end of loop a...

Страница 9: ...oftware reinstall AKA65 software outside of Program Files or Program Files x86 folder 3 Obtain generic copy of aka65 ini file place in C Windows folder replace existing Unable to locate compatible Win...

Страница 10: ...Danfoss Climate Solutions 2022 02 BC337731384771en 000301 10...

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