Safety; Short Circuit And Protection - Philips OccuSwitch DALI LRM2070 Datasheet

LRM2070, LRM2080, LRM2090 Datasheet
OccuSwitch DALI sensor/controller

Safety

The OccuSwitch DALI uses DALI or DALI-like signals to
communicate to other devices, drivers or BMS systems.
The interfaces (DA and X) on the OccuSwitch DALI have
additional isolation from mains (SELV). However most DALI
devices (like drivers in luminaires) only provide basic isolation
between mains and DALI. Therefore to avoid installation safety
issues, all interface wiring (also on the X-Interface) should be
treated as FELV, so mains-rated isolation is required.
We strongly recommend to always use cabling with mains-
rated isolation to prevent potentially unsafe installations.

Short circuit and protection

The DA (all units) and X (LRM2070 and LRM2080) interface
provides DALI (or other) power in order to be able to
communicate. These interfaces are protected against a short
circuit if used within specification. External power (DALI)
supplies can only be used on the BMS DALI network of the
LRM2090 (X-interface). The use of more than 22 LRM2080
units in parallel connected on the X-interface can damage the
X-interface circuit. The network (X) interface of the LRM2090
has extended protection against mains connection. For all
OccuSwitch DALI devices, the DA and X interface (except
X-interface on LRM2090) will be damaged beyond repair if
mains power is connected. Although safe, smoke and a strong
smell can occur if this happens.
Parallel mode
The LRM2080 OccuSwitch DALI advanced supports parallel
mode for occupancy control (X-interface). This means that
the separate units have their own daylight-depending and
local control and their own settings. Only the MD signal from
connected units is shared. This means that lights will stay on if
one of the connected systems detects movement. Lights will
stay on and only switch off, or go to background level when
the last MD timer in the group elapses.
The exception to this rule is mode 9. The parallel link is
refreshed every 60 seconds. So when movement is detected a
signal will be given, then after 60 seconds repeatedly, until the
timer elapses. This signal is visible on the unit.
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