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EN-Rev IM/GN-BM-EU/1.8 Copyright © March, 2021. CSI Solar Co., Ltd.
www.csisolar.com
Table 1: Low temperature correction factors for open-circuit voltage
Lowest Expected Ambient Temperature (°C/°F)
Correction Factor
24 to 20 / 76 to 68
1.02
19 to 15 / 67 to 59
1.04
14 to 10 / 58 to 50
1.06
9 to 5 / 49 to 41
1.08
4 to 0 / 40 to 32
1.10
-1 to -5 / 31 to 23
1.12
-6 to -10 / 22 to 14
1.14
-11 to -15 / 13 to 5
1.16
-16 to -20 / 4 to -4
1.18
-21 to -25 / -5 to -13
1.20
-26 to -30 / -14 to -22
1.21
-31 to -35 / -23 to -31
1.23
-36 to -40 / -32 to -40
1.25
Alternatively, a more accurate correction factor for the
open-circuit voltage can be calculated using the following
formula:
𝐂
Voc
= 𝟏 − 𝜶
𝑽𝒐𝒄
× (𝟐𝟓 − 𝐓)
T (°C) is the lowest expected ambient temperature at the
system installation site.
α
Voc
(%/°C) is the voltage temperature coefficient of the
selected module (refer to corresponding datasheet).
OCPD rating selection should be done per the following
guidance, where the minimum OCPD rating possible is
determined by calculating the expected maximum circuit
current for the PV system, and the maximum OCPD rating
constrained by the IEC 61215: 2016 and UL 1703: 2018
standard requirements for the certified PV modules.
Minimum string fuse rating < X ≤ Maximum string fuse
rating.
The maximum string fuse ratings can be found in ANNEX
A: Mechanical and Electrical Ratings for all the certified
Canadian Solar bifacial module types.
The minimum string fuse rating for compliance with NEC:
2017 code and IEC 62548: 2016 requirement is suggested
to be determined as follows:
Minimum string fuse rating = Isc
STC
x 1.25 x Max (1.175,
Impp
α
÷ Impp
STC
).
Impp
α
= the highest 3-hour current average resulting
from the simulated local simultaneous irradiances on
the front and rear sides of the PV array accounting for
elevation and orientation.
Isc
STC
= the listed short circuit current at 0% bifacial gain
on the PV module datasheet or nameplate label.
Impp
STC
= the listed MPP operating current at 0%
bifacial gain on the PV module datasheet or nameplate
label.
An assembly, together with its overcurrent device(s), that
is listed for continuous operation at 100 percent of its
rating shall be permitted to be used at 100 percent of its
rating, and therefore shall not require the additional 1.25
multiplier.
Electrical calculations and design must be performed by a
competent engineer or consultant.
Please contact Canadian Solar’s technical support team
for additional information pertaining to engineering
optimization and approval of project specific module
string lengths.
4.0 UNPACKING AND STORAGE
PRECAUTIONS
Modules should be stored in a dry and ventilated
