User manual

4 
TDK-Lambda 
LS 25-150 Series 
INSTRUCTION MANUAL 
4. Isolation / Withstand Voltage 
4-1. Isolation Test 
Isolation resistance between output and FG (chassis) shall be more than 100MΩ at 500VDC. For safety, voltage setting 
of DC isolation tester must be done before the test. Ensure that the unit is fully discharged after the test. 
(a)  Output ~ FG (chassis) : 500VDC, 100MΩ or more 
AC(L) 
AC(N) 
FG
+ V
+V
- V
- V
Isolation 
Tester 
4-2. Withstand Voltage 
This series is designed to withstand 3.0kVAC between input and output, 1.5kVAC between input and FG (chassis) and 
500VAC between output and FG (chassis) each for 1 minute. When testing withstand voltage, set current limit of with-
stand voltage test equipment at 20mA ( Output-FG (chassis) : 100mA ). The applied voltage must be gradually increased 
from zero to testing value and then gradually decreased for shut down. When timer is used, the power supply may be 
damaged by high impulse voltage at timer switch on and off. Connect input and output as follows : 
(a) Input ~ FG (chassis) : solid line            (c) Output ~ FG (chassis) : 500VAC, 1min (100mA)     
1.5kVAC, 1min (20mA) 
(b) Input ~ Output : dotted line 
 3kVAC, 1min ( 20mA )           
AC(L) 
AC(N)
FG 
+V
+V
-V
-V
Withstand 
Voltage 
Tester
AC(L) 
AC(N) 
FG
+V
+V
-V
-V
Withstand
Voltage 
Tester 










