As this is in Canada, IF the install is compliant with the CEC, it also conforms to the mfg. install guidelines.
"2.1.4 Wiring
Turn OFF the power to the electrical distribution
equipment where the CPS Filter is to be installed.
Install a branch circuit breaker to feed the CPS filter
device for ease of installation. The unit contains UL
and CSA approved fusing to protect against short
circuit fault conditions within the device.
Over current protection is not specifically required,
although most customers choose to install a circuit
breaker as a disconnect device on panelboards or
switchgear assemblies. (See Table 2 for suggested
circuit breaker size). Follow NEC, CEC and applicable
local codes when connecting the CPS directly to the
Bus Bar."
IMHO, a branch circuit CB as suggested within the guidelines would be the way to go, and how all I have seen are installed.
