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Primary unit vs Secondary unit 18 of 20 identical Swap Change inverters

SolarEdge SE66.6K (K66.6SE) - Primary unit vs SolarEdge SE66.6K (K66.6SE) - Secondary unit

SolarEdge SE66.6K (K66.6SE) - Primary unit
SolarEdge
SolarEdge SE66.6K (K66.6SE) - Primary unit
66.6 kW 98.0 % euro Grid-tie
Open inverter page Datasheet PDF
VS
SolarEdge SE66.6K (K66.6SE) - Secondary unit
SolarEdge
SolarEdge SE66.6K (K66.6SE) - Secondary unit
66.6 kW 98.0 % euro Grid-tie
Open inverter page Datasheet PDF
The verdict

Secondary unit leads on the differences that matter

The largest is weight: 3.0 kg lighter. 18 of 20 comparable parameters are identical, with 12 more left out because at least one datasheet does not publish them.

See all 2 differences
How alike are they
18 of 20 comparable
parameters are identical
identical differs not published
01

What actually differs

2 of 20 parameters
Parameter Primary unit Secondary unit Difference
Weight 48.0 kg 45.0 kg 3.0 kg lighter
Dimensions 940x315x260 mm 540x315x260 mm 940x315x260 mm vs 540x315x260 mm
02

Full specification

Parameter Primary unit Secondary unit Difference
AC output
Rated AC power 66.60 kW 66.60 kW Same
Max AC power 66.60 kW 66.60 kW Same
Grid connection 3-phase 3-phase Same
Nominal AC voltage 480 V 480 V Same
Max AC current 80.0 A 80.0 A Same
PV input
Max PV power 90.00 kW 90.00 kW Same
DC/AC ratio 1.35 1.35 Same
Max DC voltage 1000 V 1000 V Same
MPPT voltage range - - Neither datasheet publishes this
Start voltage - - Neither datasheet publishes this
MPP trackers - - Neither datasheet publishes this
Strings per tracker - - Neither datasheet publishes this
Max input current per tracker - - Neither datasheet publishes this
Efficiency
European efficiency 98.0 % 98.0 % Same
Max efficiency 98.1 % 98.1 % Same
CEC efficiency - - Neither datasheet publishes this
Battery
Battery input - - Neither datasheet publishes this
Battery voltage - - Neither datasheet publishes this
Max charge current - - Neither datasheet publishes this
Backup power - - Neither datasheet publishes this
Physical
Weight 48.0 kg 45.0 kg -3.0 kg for Secondary unit
Weight per kW 0.7 kg/kW 0.7 kg/kW Same
Dimensions 940x315x260 mm 540x315x260 mm 940x315x260 mm vs 540x315x260 mm
Ingress protection IP65 IP65 Same
Cooling forced-air forced-air Same
Noise 60 dB 60 dB Same
Max operating temperature 60 °C 60 °C Same
Connectivity and safety
Wi-Fi - - Neither datasheet publishes this
Ethernet Yes Yes Same
Arc fault protection Yes Yes Same
Integrated DC switch Yes Yes Same
Warranty
Warranty - - Neither datasheet publishes this
03

More useful comparisons

Open all inverters
Same type, similar size
SolarEdge
SolarEdge SE66.6K (K66.6SE) - Primary unit vs SolarEdge SE66.6K (K66.6SE)
One difference: dimensions
Same type, similar size
SolarEdge
SolarEdge SE66.6K (K66.6SE) - Primary unit vs SolarEdge SE66.6K (Synergy, 277/480V)
The same specification on paper
Same type, similar size
SolarEdge
SolarEdge SE66.6K (K66.6SE) - Primary unit vs SolarEdge SE66.6K (Synergy) - secondary unit (physical)
2 differences, the largest is weight
04

Written summary

Every figure here is from the manufacturers' own datasheets - a dash means the value is not published, never an estimate.