SM3000
DELTA ELEKTRONIKA BV
1991, rev. May 2008
DESCRIPTIONS
Page 3 - 5
18)
IN SU LA TION
For safety the in su la tion of the sep a rat ing com po nents (trans-
formers) be tween in put and out put is tested at 3750 Vrms dur ing
1 min ute. This is tested be fore as sembling.
Warn ing!
The 3750 Vrms can not be tested af terwards on the
as sem bled unit be cause the in su la tion be tween the com po -
nents on the in put side to the case (like the bridge rec tifier) is
spec i fied at 2500 Vrms. Since the in sulation out put - case is low
(only 600 V DC) the in sulation of the pri mary components to
case will break down when 3750 Vrms is ap plied be tween in put
and out put (2500 Vrms + 600 V DC < 3750 Vrms) (see also fig. 3
- 17).
Note:
when testing the in sulation, take care to charge and dis -
charge the capacitors be tween in put - case and out put - case
slowly (e.g. in one sec ond). This to prevent high peak currents,
which could de stroy the power sup ply. Make sure to have dis -
charged the capacitors completely be fore us ing it again.
19)
RFI SUP PRES SION
Both the in put and out put have RFI fil ters, re sulting in very low
conducted RFI to the line and load. Due to the out put fil ter the
output voltage is very clean, hav ing al most no spikes.
20)
OP ER ATING TEMP
At full power the op erating tem perature range is –20 to +50 °C.
From 50 to 60 °C the output cur rent has to be de rated lin early to
75 % at 60 °C (see fig. 3 - 18). These tem peratures hold for nor -
mal use, i.e. the ven tilation open ings on the left and right side
must be free.
21)
THER MAL PRO TEC TION
A ther mal switch shuts down the out put in case of in sufficient
cooling. After cool ing down the unit will start work ing again.
The thermal pro tection circuit pro tects 2 parts sep arately in the
unit: the switching tran sistors on the pri mary side and the out put
cir cuit.
A trip ped ther mal pro tection can have the fol lowing ef fects:
1) When the pro tection on the switching tran sistors has trip ped,
no led in dicator or digital me ter will burn on the front panel.
2) When the pro tection on the output cir cuit has tripped, the
OVP led on the front panel will burn, and the OVP sta tus output
will be high.
22)
HOLD - UP TIME
The hold - up time de pends on the load, out put voltage and line
input voltage. A lighter load, a lower out put voltage or a higher
line in put voltage all re sult in a lon ger hold - up time (see fig.
3 - 19).
23)
TURN ON DE LAY
The out put voltage is avail able 0.5 sec after mains switch on.
24)
IN RUSH CUR RENT
The in rush current is limited by a 90 Ohm re sistor, re sulting in a
very low current dur
ing switch on. The in
put cur
rent dur
ing
switch on will be lower than dur ing op eration at full load.
25)
PHASE LOSS
Phase loss means that there is only one phase avail able in stead
of three.
The unit will con tinue to op erate on one phase but at 90% of the
max. out put volt age. Ex.: a SM30-100D on one phase 380 V can
deliver 90% x 30 = 27 V @ 100 A. So if the output voltage is not
set higher than 27 V no drop in the output voltage will be noted
during phase loss. How ever the output rip ple volt age will be
slightly higher when the in put is on one phase.
fig. 3 - 16
Remote sensing on a pulsating load
fig. 3 - 17
In su la tion test voltages
fig. 3 - 18
Op er ating temper a ture ranges
fig. 3 - 19
Hold-up time vs Vout with Vin as a parameter
