TDI UltraFLEX HD, User Manual

 
 
 
U L T R A F L E X   H D   P D U   U S E R   M A N U A L  

708401 Rev B 

Page 31 of 38 

3.9.2.2

AC Available 

The AC available signal monitors phases B & C of the AC from the input side of circuit breaker CB1. The AC 
available LED’s will be illuminated green provided that both EMO breaker CB2 is on and the AC voltage is 
above 170 VAC. 

 
WARNING:  IF EMO BREAKER IS OFF, THERE WILL BE NO INDICATION 
AC IS PRESENT WITHIN THE PDU.  WHENEVER WORKING ON THE PDU 
ALWAYS FOLLOW LOCK OUT TAG OUT PROCEDURES AND MEASURE 
FOR VOLTAGES BEFORE PERFORMING ANY WORK. 

3.9.2.3

Main Power On 

The Main power on signal monitors phases B & C of the AC on the output side of circuit breaker CB1. The 
Main power on LED will be illuminated green provided that both input breaker CB1 is on and the AC voltage 
is above 170 VAC. 
 

3.9.2.4

48V DC on 

The 48V DC on signal monitors the 48V DC output.  The 48V DC on LED will be illuminated green 
whenever the 48V DC output voltage is above 44 VDC. 
 

3.9.2.5

Power Supply LED’s 

The interface PCB contains LED’s to show the status of the power supplies.  When the 48V DC bus is 
enabled, all installed power supplies should have their corresponding LED illuminated green.  If a power supply 
is not installed or failed, the corresponding LED will be off.  All power supply LED’s will be off when the 48V 
bus is inhibited (off).  Refer to 

Figure 22

 for a view of the rectifier good LED’s. 

3.9.3

Test Points 

Test points are provided on the interface PCB as shown in 

Figure 22

.  There is one set of test points for the 

24V EMO supply output and one set for the 48V DC output.  The test points are protected against short 
circuit by re-settable fuses.  For all test points, red is positive and black is negative. 
 
 

3.9.4

Thermostat 

A normally closed thermostat is located on the interface PCB which will shut down the PDU due to extreme 
temperatures.  The thermostat is rated 45

°

C +/- 5

°

C and is installed in the positive leg of the 24V EMO power 

to the EMO loop.  If the temperature reaches the thermostat set-point, the thermostat will open and trip input 
breaker CB1 resulting in the shut down the PDU.  The thermostat will automatically reset after the temperature 
has reached about 35 degrees C, but the PDU will remain off since the input breaker will need to be turned on.  
T

he thermostat should re-set within 1 minute as long as the temperature is 4 degrees below the trip range (trip range 

is 40C - 50C). 

The PDU will not be able to be turned on until the thermostat has reset.  As shown in 

Figure 24

, 

the thermostat is located on the interface PCB, behind the test points.  To check if the thermostat is 
open/closed, refer to section 2.1 (item 7) of the Service Manual.