Editing Argon supply voltage troubleshooting

If there's problem getting rid of permanent under voltage fault in [[Argon]], it may be caused by following reasons:
*[[Safe torque off|STO1]] input is not powered by 24 VDC
*Drive's internal fuse has blown. To check this [[Argon user guide/Power supply safe discharging|safely discharge drive]], remove cover, remove fuse and measure fuse resistance. If high current & power is demanded from the drive, then a higher amperage fuse may be installed in the place of original. Maximum fuse size is 16A slow blow and the factory default is between 6.3-8 A slow blow.
*Other failure in AC power path, see below for details.
==Drive internal AC circuity==
[[File:Argon ac input.png|800px]]

Inrush current limiter is based on a resistor which is bypassed by a [[GraniteCore]] controlled relay after HV DC supply has risen near nominal levels.

Verifying internal [[HV DC bus]] voltage can be done by reading the voltage value from Granity Testing tab '''or''' by measuring DC voltage between VP and VN terminals. The voltage between VP and VN is directly connected to the power stage, so if there is voltage between these terminals, then drive's HV supply is properly powered and it is possible to drive motor.

==Checking for AC to HV DC signal path components==
{{Electricshock|Before proceeding with the tests, make sure drive has been safely discharged for at least 15 minutes before opening it. Any remaining voltage in the device may interfere the measurements here. See more info [[Power supply safe discharging|here]].}}
===STO1===
Applying 24V voltage to STO1 inputs causes the STO relay to emit a relay ''click'' sound. If there is no sound, then the reason is related to STO1 relay or it's control.
===Fuse F1===
Open drive case and check conductivity of fuse F1.
===Inrush current limiter resistor R7===
R7 is a 5W resistor from 33 to 100 ohm that conducts current to charge bulk capacitors. After capacitors are charged to full, relay RL2 is closed to allow high current flows. 

Resistance of R7 can be measured with multimeter from test points marked in the image. The correct reading is the marked resistance +/- 2 ohm. It is possible to replace (desolder and solder) new resistor without removing heatsink from the PCB by approaching PCB from the side of the board.

It is recommended to replace R7 with similar size 5W 100 ohm resistor such as {{Farnell|987645}}
[[File:Argoninrushlimiter.jpg|thumb|Resistor R7 measurement points inside Argon]]
====Reason for R7 burn====
*R7 will burn (open circuit) if there is malfunction in relay RL2 (relay stuck in off-state).
*R7 will burn open if power is consumed from HV DC bus while relay RL2 is open (so drive tries to charge capacitor bank through this resistor without but voltage does not rise). This is possible if something is drawing power from VP and/or VN terminals. This could be another drive shared in the same bus, or for example a loose wire strand shorting wrong terminals in J4 connector.
*Another causes might be a damaged power stage or regenerative drive (some transistors short circuited) of drive, which also would load HV DC bus continuously. To identify if this has happened, see [[Determining Argon hardware failure]].

Drive firmware disables power stage and regenerative resistor drive always when RL2 is open, but it can't prevent resistor burn in case of the conditions mentioned above.

===AC/DC rectifier bridge B3===
Measuring condition of B3 is possible with multimeter's diode check function. Check all four diodes from the test points marked in the image. Multimeter red lead goes to anode and black to cathode. All diodes should give reading of 0.4 to 0.5 Volts.
[[File:Argondiodebridge.jpg|thumb|Diode bridge B3 measurement points circled]]