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Chapter 4: SMI Connections
Up to 10 SMIs may be connected to each inverter (MPP tracker). The DC out cables
connect the SMI to the inverter. Connection to the inverter is the last stage of
installation.
Connecting the DC Out Cables to the SMI
1. Turn OFF the SMI ON/OFF switch and the DC breaker between the SMI and modules
(if applicable).
The SMI enters the SafeDC™ mode and displays the following message. This
message is displayed until the DC voltage is safe (50V).
If the SMI was operating properly (power was produced by the power optimizers),
the following message is displayed.
D C V O L T A G E N O T S A F E
D O N O T D I S C O N N E C T
V D C : 7 2 . 0
WARNING!
Do not open the cover or touch the DC power connections until the
voltage is safe or until at least five minutes have passed. Doing so may
cause injury or loss of life, damage to the device and/or danger of fire.
2. Turn OFF the PSU.
3. Switch the AC to the inverter OFF (as described in its manual). If applicable, turn the
inverter DC Safety Switch to OFF.
4. Open the lower compartment of the SMI as described in
5. Use a 5/16" Allen key to loosen the screws of the SMI DC power distribution blocks.
6. Remove the seals from the glands labeled DC+OUT/DC-OUT.
7. If the cables that will connect to the inverter are 18-25 mm in diameter, insert the
wires through the opening.
If the cables are less than 18 mm in diameter, replace the rubber seals in the gland
with the rubber seals supplied in the SMI package, and insert the wires through the
opening.
8. Connect the cables to the DC+ and DC- output connectors as indicated.
SMI-180 Installation Guide MAN-01-00157-1.1
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Chapter 4: SMI Connections