Progress Solar/Wind SLT 700 Series Operator's Manual page 110

REQUIRED OVERCURRENT PROTECTION DEVICES (OCPD) AND DISCONNECT
SWITCHES
WARNING: Risk of Fire
Solar and battery overcurrent protection (breakers or fuses) are required in the system. These protec-
tion devices are external to the TriStar MPPT controller, and must be sized as required by the NEC or
local code requirements.
WARNING: Shock Hazard
The PV system requires a means of disconnecting the battery and PV array. Breaker switches or dis-
connect switches can serve as a disconnecting means and should be located at a readily accessible
location. For best practices and safety guidance see NEC 690 "Part III - Disconnecting Means" for
disconnect requirements for PV systems in addition to other code requirements.
WARNING: Shock Hazard
Fuses, single-pole circuit breakers, or single-pole disconnect switches must only be installed on
ungrounded system conductors. The NEC allows and may require the use of double-pole breakers or
double-pole disconnect switches which break both the grounded and ungrounded conductors of the
PV array.
WARNING: Risk of Fire
Maximum battery short-circuit current rating must be less than the interrupt current rating of the bat-
tery over-current protection device.
BATTERY DISCONNECT AND OVER-CURRENT PROTECTION DEVICE SIZING
The U.S. NEC requires the installation of DC breakers or fused disconnect switches in all battery
circuits in order to provide both a means of disconnection and overcurrent protection.
The battery breaker or fused disconnect switch(es) should be located near the battery or the battery
busbar. Where the controller battery terminals are more than 1.5m (5 feet) from the battery, or where
circuits from these terminals pass through a wall or partition, U.S. NEC requires that a means of dis-
connection be provided at the battery and solar controller with overcurrent protection at the DC (bat-
tery) power source.
The minimum battery disconnect switch current rating is the current rating of the controller being
installed. To provide over-current protection when using a disconnect switch, a properly sized fuse or
breaker must be installed in series.
Battery breakers or fuses must be sized with a minimum of 125% of the continuous output current
rating of the solar controller. Recommended battery circuit fuse or breaker current ratings:
TS-MPPT-30: 40 Amps
TS-MPPT 45: 60 Amps
TS-MPPT-60/M: 75 or 80 Amps
PV INPUT DISCONNECT AND OVER-CURRENT PROTECTION DEVICE SIZING
WARNING: Shock and Fire Hazards
The solar array open-circuit voltage (Voc) at the worst-case (coldest) module temperature must
not exceed the PV disconnect or overcurrent protection voltage ratings.
30 Installation
As defined in NEC Section 690.9, PV input disconnect switches must have a current rating great-
er than or equal to the maximum PV array current (PV array Isc multiplied 1.25). PV array Isc =
number of strings multiplied by the module Isc (STC) rating. Note that individual PV string circuits do
not require disconnects.
NEC Section 690.9 also provides requirements for overcurrent protection. The PV input breaker or
fuse current rating should not be less than the next higher breaker rating above 125% of the maxi-
mum PV array current (156% of the PV array Isc). Maximum PV breaker or fuse ratings are:
TS-MPPT-30: 40 Amps
TS-MPPT 45: 60 Amps
TS-MPPT-60/M: 80 Amps
String over-current protection is also required for parallel strings and are typically included with the PV
string combiner. There may be other code requirements specific to the installation of a particular PV
array.
If 156% of PV array Isc is greater than the maximum PV input breaker or fuse current rating, the
PV array breaker or fuse should be located at the output of the PV array combiner.
CONNECT THE POWER WIRES
WARNING: Shock Hazard
The solar PV array can produce open-circuit voltages in excess of 150 Vdc when
in sunlight. Verify that the solar input breaker or disconnect has been opened
(disconnected) before installing the system wires.
AVERTISSEMENT : Risque de décharge électrique
Le réseau PV solaire peut produire des tensions de circuit ouvert supérieures à 150
Vdc à la lumière du soleil. Vérifiez que le coupe-circuit ou l'interrupteur d'entrée
solaire a été ouvert (déconnexion) avant d'installer les câbles du système.
Solar + Solar -
Battery -
(Common Negative)
Figure 3-7. Power terminal locations
TriStar MPPT Operator's Manual
Battery +
31