User manual

DLM4000_Bed_Anleitung_v1.2_oce_eng.doc; 16.06.2009; M.Billmann; 7/13
3.3 Warning hint, exclusion of liability
This unit monitors dangerous voltages and indicates them visually to
laboratory staff.
Warning
The DLM4000 may show low or no DC link voltage if
- the box is damaged;
- cables are damaged, or not proper connected to the DC link.
Always use redundant elements to double check DC link
voltage.
Always provide sufficient cooling for unit. Never thermally
isolate the back side of the box. Ambient temperature must
not exceed 40°C
Any liability for damages and injuries caused by the use of this DC link
monitor DLM4000 is excluded!
4 Functional description
The DLM4000 is designed as a two channel DC link monitor to check for
dangerous voltages at a DC link or other capacitor banks.
The analog display operates as a moving coil instrument and directly
indicates voltages from zero up to 150V
DC
. If voltage exceeds, the needle
reaches a red zone. This zone is linear up to a DC link voltage level of
300V
DC
and tolerates voltages up to 3,500V
DC
max. At levels exceeding
300V
DC
the display will remain in maximum red bar position.
Once a voltage >35V
DC
is applied, the two groups of red LEDs start to flash.
They additionally indicate presence of dangerous voltage.
At levels lower than typ. 25V to 30V the red LEDs stop flashing and the
green LED bar starts illuminating. They will remain illuminated until DC link
voltage levels lower than typically 20V.
Any laboratory staff should always watch at least two redundant connected
and operating systems. To check proper discharge and correct function of a
DLM4000, analog instrument and red flashing LEDs must be observed.
When discharging the DC link the red LEDs must keep flashing while the
analog instrument shows DC link voltage decreasing. When low voltage is
reached the green LED bar must illuminate until DC link voltage reaches a
level lower than typ. 20V. After this the box discontinues electrical operation
[power down].