User guide
  User Guide – DOC-004g 
USER GUIDE – REF. PSF-241 
POWER SUPPLY/CHARGER – 24V DC 1 AMP UNIT 
General
This power supply unit is for powering a 24V DC l amp load (750 mA load + 250mA charge). It also incorporates a 
24V DC charger for use with Sealed Lead Acid Batteries up to 7ah. If the unit is being used to supply a load and 
charge batteries, the total load should not exceed lamp. If the unit is being used to supply a load only, without standby 
batteries, it is necessary to fit a resistor (value 10k ohm – ½ watt) across the battery terminal block instead of the 
battery leads. The unit should be fitted in an upright position on a solid surface using the fixing holes provided. 
The PSF-241 has a volt free relay fitted that will de-energise if any fault occurs 
The PSU-400 has a volt free relay fitted that will de-energise on mains fail only. 
Supply
Supply to the unit should be 240V ac 50Hz and an earth should be fed to the unit via a 5amp-fused outlet 
fitted adjacent to the unit. The mains supply in the enclosure should be wired into the fused terminal block 
next to the PCB. The unit should be earthed. 
PCB CONNECTIONS 
 0   0     0   0 
   +  -    +   - 
 Battery  Output 
Lid Indicators
Green = Supply Healthy  Amber = Fault  
When the Green light only is illuminated, the unit is operating normally with supply to the load and the 
batteries (when fitted) are receiving charge current. When the Amber light is illuminated at the same time as 
the Green light there is a fault on either or both of the output supply and the charge supply. If the Green light 
is NOT illuminated, the mains supply is not present or the main “overload” fuse has blown. 
PCB Fuses
  F.1. Battery = 1 Amp    F.2. = 1Amp 
PCB Indicators
  Amber (upper) = Short circuit fault/supply fault. 
  Amber (lower) = Charge output fault. 
Upper indicator illuminated, this will be caused by either, a short circuit in the wiring, or an excessive load. 
Lower indicator illuminated will be caused by blown fuse (bottom) in the battery charge output (i.e. Short 
circuit of the battery leads) or by output supply short circuit. It is essential the battery is not fitted 
“REVERSE POLARITY” as this will cause damage to the charging circuit which may be irreparable. 
Fault Find Matrix 
Mains 
 ok 
Mains 
 fault 
Output 
 Ok 
Output 
 fault 
Charger 
 Ok 
Charger 
 fault 
LED Green 
 Y   N   Y   Y   Y   Y 
LED Amber 
 N   N   N   Y   N   Y 
PCB Upper 
 N   N   N   Y   N   N 
PCB Lower 
 N   Y   N   N   N   Y 
Fault Relay: if fitted 
 N   Y   N   Y   N   Y 

