SMA 20000TL - Manual (Page 40)

9 Disconnecting the Inverter from Voltage Sources
Prior to performing any work on the inverter, always disconnect it from all voltage sources as
described in this section. Always adhere to the prescribed sequence.
Damage to seals on the enclosure lids in subfreezing conditions
If you open the upper and lower enclosure lids when temperatures are below freezing, the
enclosure seals can be damaged. This can lead to moisture entering the inverter.
• Do not open the inverter at ambient temperatures lower than -5°C.
• If a layer of ice has formed on the seal of the lid when temperatures are below freezing,
remove it prior to opening the enclosure lids of the inverter (e.g. by melting the ice with
warm air). Observe the applicable safety regulations.
Destruction of the measuring device due to overvoltage
• Only use measuring devices with a DC input voltage range of 1,000 V or higher.
Procedure:
1. Disconnect the circuit breaker from all three line conductors and secure it against
reconnection.
2. Turn the DC load-break switch to the position O.
3. If the multifunction relay is used, switch off any supply voltage to the load.
4. Wait until the LEDs have gone out and, if necessary, the load connected to the multifunction
relay has been switched off.
5. Use a current clamp to ensure that no current is present in the DC cables.
9 Disconnecting the Inverter from Voltage Sources SMA Solar Technology AG
Operating Manual STP20-25TL-BE-en-12 40