index reference app_notes hvfe_high_source_current_mod
HVFE high source current modification
HVFE modification instructions to use the high current sensor as a source current sensor.
These are instructions on modifying a remote front end to use its high current sensor (50 A, 100 A or 200 A) as a source current sensor instead of as a load current sensor.
In order to make this modification, you need to have good soldering skills, to make a small modification to the HVFE.
These instructions are applicable to remote HVFEs or BMS controllers with HVFE, with a high current sensor.
They are also applicable if the HVFE has 2 current sensors, though the low current sensor will not be useable.
This modification requires that a cable mounted current sensor is used to measure the load current.
These instructions are applicable to the following part numbers:
- HVFEs with high current sensor: 2HR0050, 2HR0100, 2HR0200
- BMS controllers with HVFE with high current sensor: 2CN0050, 2CN0100, 2CN0200
- HVFEs with 2 current sensors: 2HR0055, 2HR0070, 2HR0105, 2HR0120, 2HR0205, 2HR0220
- BMS controllers with HVFE with 2 current sensors: 2CN0055, 2CN0070, 2CN0105, 2CN0120, 2CN0205, 2CN0220
These instructions are applicable to remote HVFEs with hardware rev E.
The rev level is the last letter (followed by 2 digits) in the part number, which is written on the 7-pin white connector.
These instructions are applicable to remote HVFEs with software rev 1.04 (07/06/10) and above, which was programmed into 2HRxxxxxExx and above.
- If encased, open the case that contains the HVFE.
- Find the locations marked R36 and R37, next to the microprocessor (U4) and the large, silver capacitor (C16);
there are no component in those locations, just pads
- Use a temperature controlled soldering iron, at low temperature, with a fine tip
- For each location, short the 2 pads together with a solder bridge;
do not use too hot a soldering iron, or the solder will bead on each pad and not form a bridge
if you wish, you can use a tiny, short piece of wire to ease the bridging
- If applicable, close the case back up
Solder bridges across R36 and R37.
- On the terminal, for the load current select the cable mounted current sensor
(Home / Set-up / Current sense / Load current / Current sensor / Input / On cable / Enter)
- Go to the System Status screen (Home / Status / System) to confirm that:
- The Source Current reading is from the HVFE through the CAN bus
- The Load Current reading is from the cable mounted current sensor