Download the Linux client from APC

Extract the files:
tar xvf pcns224Linux.tar.gz
Edit install.sh from line 278 to look like this:

Initialize() {
Echo "Initializing ..."
case "$OS" in
$VIMA)
Echo "This version of PowerChute Network Shutdown does not support VMWare ESX or ESXi. Please consult www.apc.com for the required version of PowerChute Network Shutdown."
exit 1
;;
$LINUX)
STARTUP=/etc/init.d/PowerChute
PCBE_STARTUP=/etc/rc.d/init.d/PBEAgent
PCS_STARTUP=/etc/rc.d/init.d/pcs
;;

Then at line 1194 add:

#Ubuntu specific
ln -s /etc/init.d/PowerChute /etc/rc0.d/K99PowerChute
ln -s /etc/init.d/PowerChute /etc/rc1.d/K99PowerChute
ln -s /etc/init.d/PowerChute /etc/rc2.d/S99PowerChute
ln -s /etc/init.d/PowerChute /etc/rc3.d/S99PowerChute
ln -s /etc/init.d/PowerChute /etc/rc4.d/S99PowerChute
ln -s /etc/init.d/PowerChute /etc/rc5.d/S99PowerChute
ln -s /etc/init.d/PowerChute /etc/rc6.d/K99PowerChute
mkdir /var/lock/subsys/

Run the configuration script.

/opt/APC/PowerChute/group1/PCNSConfig.sh

Start the service

sudo /etc/init.d/PowerChute start