S019 
CAUTION: 
The power-control button on the device does not turn off the electrical current supplied to the device. The 
device also might have more than one connection to dc power. To remove all electrical current from the device, 
ensure that all connections to dc power are disconnected at the dc power input terminals.
S029 
DANGER
For -48V dc power supply, electrical current from power cords is hazardous.  
To avoid a shock hazard:
•  To connect or disconnect -48V dc power cords when you need to remove/install redundancy 
power supply unit(s).
To Connect: To Disconnect:
1.  Turn OFF subject dc power source(s) and equipment 
(s) that are attached to this product.
2.  Install the power supply unit(s) into the system 
housing.
3.  Attach dc power cord(s) to the product.  
•  Ensure correct polarity of -48 V dc connections: 
RTN is + and -Vin (typical -48 V) dc is -. Earth 
ground should be connected very well.
4.  Connect dc power cord(s) to subject power source 
(s).
5.  Turn ON all the power source(s).
1.  Disconnect or turn off the subject dc power source(s) 
(at the breaker panel) before removing the power 
supply unit(s).
2.  Remove the subject dc cord(s) and make sure the 
wire terminal of power cord(s) is insulated.
3.  Unplug the subject power supply unit(s) from the 
system housing.
Remove a power supply unit
Follow instructions in this section to remove a power supply unit.
About this task
If the power supply unit to be removed is the only one installed, the power supply unit is non-hot-swap. 
Before removing it, you must turn off the server first. To support redundancy mode or hot-swap, install an 
additional hot-swap power supply unit.
Attention: 
170
ThinkSystem SR665 V3 User Guide