The CSI 23/28KTL-CT/US-480 is a Canadian Solar transformerless three-phase string inverter family. It comes in a 23 kW model and a 28 kW model. Both models accept up to 1000 Vdc and have two MPP trackers with four DC inputs each. A load-rated DC switch handles DC disconnection. The MPPT range is 480-800 Vdc on the 23 kW model and 500-800 Vdc on the 28 kW model. Maximum input current per MPPT is 25 A and 29 A. The AC output is 480 Vac, 60 Hz, three-phase with neutral and PE. Maximum output current is 27.7 A on the 23 kW model and 33.7 A on the 28 kW model. Peak efficiency is 98.6 percent and CEC efficiency is 98.0 percent. Power factor can be adjusted, and output derates at high temperature. For communication the inverter uses Modbus over RS485. Firmware can be upgraded from a USB disk through the communication board's USB port. An Arcboard provides arc fault detection. An Arcboard Err fault points to poor contact or damage on that board. Clear it with ARCFaultClear after checking the board.
<!-- review notes
manufactured_byc1 drafted · lead Canadian Solar
sec=front h=f3b9d2a73eefreview note: support check: partial - Evidence is only the bare string 'CanadianSolar', which suggests but does not state the manufacturer relation.
instance_oftbl=34.r1 h=a154a490818auses_protocolsec=3.3.3 h=ee92d25ee20aRS485 cable: UTP CAT-5e or 3x #22-18 AWG communication cable, e.g. Belden 3106A.
sec=3.3.3 h=ee92d25ee20atbl=16.r1 h=35ca3a947813implementsc5 drafted · lead Maximum power point tracking
Two MPP trackers per model, with four DC inputs on each MPPT.
tbl=32.r4 h=beb0303611datbl=32 h=8bdf6fbb3f1fc6 drafted · lead DC arc-fault protection
Uses an Arcboard; arc faults are cleared with the ARCFaultClear command.
tbl=31.r2 h=2a8f07023fcfreview note: support check: partial - The Arcboard error and ARCFaultClear are in the passage, but it never states that the inverter provides DC arc-fault protection.
c7 drafted · lead Constant power factor mode
Power factor above 0.99, adjustable to plus or minus 0.8.
tbl=32.r10 h=ad5edc9d8ce8tbl=32 h=8bdf6fbb3f1freview note: support check: partial - The table gives a power factor of >0.99 and ±0.8 adjustable, but it does not name a constant power factor mode.; review: partial - The table gives power factor >0.99 and adjustable to ±0.8, which matches the note, but it never names a constant power factor mode.
rated_powerc8 drafted · lead nominal 23 KiloW
Conditions: CSI 23KTL-CT/US-480, rated AC output power
tbl=32.r8 h=ccb247cee4abtbl=32 h=8bdf6fbb3f1freview note: possible conflict with c9 (same source; check the conditions)
c9 drafted · lead nominal 28 KiloW
Conditions: CSI 28KTL-CT/US-480, rated AC output power
tbl=32.r8 h=ccb247cee4abtbl=32 h=8bdf6fbb3f1freview note: possible conflict with c8 (same source; check the conditions)
max_input_voltagec10 drafted · lead nominal 1000 V
Conditions: Both models, maximum DC input voltage
tbl=32 h=8bdf6fbb3f1fmppt_voltage_rangeConditions: CSI 23KTL-CT/US-480
tbl=32 h=8bdf6fbb3f1fConditions: CSI 28KTL-CT/US-480
tbl=32 h=8bdf6fbb3f1fverified by: review-workflowverified on: 2026-10-24
max_input_currentc13 drafted · lead nominal 25 A
Conditions: CSI 23KTL-CT/US-480, per MPPT (Imp); total 50 A
tbl=32 h=8bdf6fbb3f1freview note: possible conflict with c14 (same source; check the conditions)
c14 drafted · lead nominal 29 A
Conditions: CSI 28KTL-CT/US-480, per MPPT (Imp); total 58 A
tbl=32 h=8bdf6fbb3f1freview note: possible conflict with c13 (same source; check the conditions)
rated_output_currentc15 drafted · lead nominal 27.7 A
Conditions: CSI 23KTL-CT/US-480, maximum AC output current
tbl=32 h=8bdf6fbb3f1ftbl=32.r9 h=5a012a8ab053review note: possible conflict with c16 (same source; check the conditions)
c16 drafted · lead nominal 33.7 A
Conditions: CSI 28KTL-CT/US-480, maximum AC output current
tbl=32 h=8bdf6fbb3f1ftbl=32.r9 h=5a012a8ab053review note: possible conflict with c15 (same source; check the conditions)
nominal_voltagec17 drafted · lead nominal 480 V
Conditions: Rated AC output voltage, three-phase with N and PE; output voltage range 422-528 Vac
tbl=32 h=8bdf6fbb3f1ftbl=32.r9 h=5a012a8ab053frequencyc18 drafted · lead nominal 60 HZ
Conditions: Rated output frequency
tbl=32 h=8bdf6fbb3f1ftbl=32.r9 h=5a012a8ab053c19 drafted · lead 59.3–60.5 HZ
Conditions: Output frequency range
tbl=32.r10 h=ad5edc9d8ce8tbl=32 h=8bdf6fbb3f1fefficiencyc20 verified · fact nominal 98.6 PERCENT
Conditions: Maximum (peak) efficiency
tbl=33.r2 h=37d602a68a89verified by: review-workflowverified on: 2026-10-24review note: possible conflict with c21 (same source; check the conditions)
c21 drafted · lead nominal 98 PERCENT
Conditions: CEC weighted efficiency
tbl=33.r2 h=37d602a68a89review note: possible conflict with c20 (same source; check the conditions)
applies_to c9applies_to c11applies_to c8applies_to c7applies_to c11applies_to c9applies_to c10applies_to c9applies_to c7applies_to c7applies_to c8applies_to c8applies_to c8applies_to c10applies_to c10