plmpower: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/sbin/plmpower - from package: powerman

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/plmpower - from package: powerman

You may install the required package with command apt-get install {package}

Error in other languages:
plmpower: bevel nie gevind nie
plmpower: comandă negăsită
plmpower: comando não encontrado
plmpower: commande introuvable
plmpower: command not found
plmpower: käsku ei ole
plmpower: không tìm thấy lệnh
plmpower: komanda nerasta
plmpower: Kommando nicht gefunden.
plmpower: kommandot finns inte
plmpower: komut yok
plmpower: nie znaleziono polecenia
plmpower: níor aimsíodh an t-ordú
plmpower: no se encontró la orden
plmpower: no s'ha trobat l'ordre
plmpower: opdracht niet gevonden
plmpower: parancs nem található
plmpower: perintah tidak ditemukan
plmpower: príkaz nenájdený
plmpower: příkaz nenalezen
plmpower: команда не найдена
plmpower: командата не е открита
plmpower: 命令找不到
plmpower: コマンドが見つかりません