SWITCH MODE DC POWER SUPPLY
REGULATED DC POWER SUPPLY
MODELS: SEC-1235
SEC-1235M
INSTALLATION & OPERATING MANUAL
Please read this manual before operating your power supply.
TABLE OF CONTENTS
Topic |
Page |
Important safety instructions |
2 |
Description and features |
3 |
Operation from AC iput voltage of 230 VAC |
3 |
Connections and operation |
4 |
Cooling fan control / thermal protection |
4 |
Battery charging and battery back up |
5 |
Trouble shooting |
6 |
Limiting electromagnetic interference |
7 |
Switching power supplies & RF noise |
8,9,10 |
Specifications |
11 |
Warranty |
12 |
CAUTION !
RISK OF ELECTRIC SHOCK
DO NOT OPEN
WARNING—TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE. THERE ARE NO USER SERVICEABLE PARTS INSIDE—REFER TO QUALIFIED SERVICE PERSONNEL.
IMPORTANT SAFETY INSTRUCTIONS
Please read before using your power supply.
1)It Is recommended that you return your power supply to a qualified dealer for any service or repair. Incorrect assembly may result in electric shock or fire.
2)To reduce the risk of electric shock, unplug the power supply from the outlet before attempting any maintenance or cleaning. Turning off controls will not reduce this risk.
3)If an extension cord is used, make sure that it has 3-prong, grounded male plug (NEMA5-15P) and 3-prong, grounded female receptacle (NEMA5-15R). The size of the current carrying conductors should be such that they are able to carry at least 10 A for the length of the extension.
4)Place the unit in an area that will allow air to flow freely around the unit. DO NOT block or obstruct vent openings on the side/bottom of the unit.
5)Keep the unit away from moisture and water.
6)NEVER OPERATE THE UNITS IN PARALLEL
WARNING! Your power supply should be grounded to reduce the risk of electric shock. The power supply comes with a detachable power cord that has a 3 prong, grounded male plug (NEMA5-15P). The round prong of the plug gets connected to the chassis of the unit. When the power cord is plugged into the corresponding 3 slot female receptacle (NEMA5-15R), the chassis of the unit is automatically connected to the earth ground through the equipment grounding conductor that is connected to the round slot of the female NEMA5-15R receptacle.
The power cord must be plugged into a NEMA5-15R outlet that is properly installed and grounded in accordance with all local codes and ordinances. Never alter the power cord that has been provided. If the plug of the cord will not fit the outlet, have a proper outlet installed by a qualified electrician. Improper connection can result in risk of electric shock.
DO NOT USE THE POWER SUPLYFOR DIRECT CHARGING OF BATTERY OR DIRECT CONNECTION TOABATTERY FOR BATTERY BACK-UP. ( Please read
the section on “Battery Charging and Battery Back-up” on page 5).
2.
DESCRIPTION
SEC-1235 / SEC-1235M are Switched Mode Power Supplies (SMPS) which convert 120 VAC, 60 Hz (or 230 V, 50 / 60 Hz *) AC power to regulated 13.8 V DC power based on Pulse Width Modulation (PWM) control.
*Note: The units are factory preset to operate from an input voltage of 120 VAC, 60 Hz. These may be set to operate from an input voltage of 230 VAC, 50 / 60 Hz. by changing internal settings as described below under “OPERATION FROM AC INPUT OF 230 VAC”
FEATURES
-Based on switched mode technology and PWM control
-Compact and light weight
-High efficiency and less heat dissipation
-SEC-1235M comes with voltmeter and ammeter
-Protected against short circuit, over load and over temperature
-Cooling by temperature controlled fan
-UL safety certified and listed under UL Standard UL60950-1 for Information Technology Equipment Power Supply
-Complies with FCC Part 15(B) for limits on EMI for Class B Digital Devices
OPERATION FROM AC INPUT VOLTAGE OF 230 VAC
These units have been preset to operate from an input voltage of 120 VAC, 60 Hz. The units can be set to operate from an input voltage of 230 VAC, 60 Hz. by changing the position of an internal jumper. The procedure for conversion to input voltage of 230 VAC, 50 Hz. is as follows:
•Switch off the unit and unplug the power cord from the AC outlet
•Remove the top cover
•For 120 VAC operation (pre-set condition), points "D" and "E" on the printed circuit board (PCB) have been connected (shorted) with a flexible wire jumper. To convert to 230 VAC input, disconnect the quick disconnect connector at point "D" by pulling it upwards. Tape this end with an insulation tape and use a cable tie to tie it securely to the wire harness running above
•The fuse on the AC side for the preset input voltage of 120 VAC is
rated at 250 V, 8 A. For 230 VAC operation, the fuse has to be rated at 250 V, 4A. Replace the existing 8 A fuse with a 4 A fuse. See under “SPECIFICATIONS” on page 11 for details on the 4 A fuse.
•The detachable power cord that is provided has an “IEC 320-13” female connector on one end that will mate with the “IEC 320-C14” male AC inlet connector on the power supply. The other end of this power cord has a 120 VAC NEMA5-15P plug meant for connection to the 120 VAC, NEMA5-15R outlet. For operation on 230 VAC, 50 Hz, a different detachable power cord will have to be used. Use an appropriate power cord that has an “IEC 320-13” female connector on one end (for connection to the “IEC 320-C14” AC inlet connector on the power supply) and a 230 VAC plug on the other end corresponding to the 230 VAC outlet. Please ensure that the new 230 VAC power cord uses two pole,
3 wire grounding configuration (this will ensure proper earth grounding).
3.
CONNECTIONAND OPERATION
WARNING ! The unit has been pre-set to operate from an input voltage of 120 VAC. Hence, before plugging the unit to the AC outlet, please ensure that the local AC power supply voltage is 120 VAC. Operation from 230 VAC is possible by changing internal settings. Please see details on page 3 under “OPERATION FROM AC INPUT VOLTAGE OF
230 VAC”
NOTE: The DC output connectors (RED + and Black -) have a tubular hole of diameter 0.2” (5mm) with a set screw. If bare wire with stranded conductors is used to connect the load to the above output connectors of the power supply, the strands will spread out as the set screw is tightened and hence, the set screw will not pinch all the strands. As a result, the effective cross section of the current conducting area of the wire will be reduced resulting in voltage drop at the load end, reduced efficiency and also overheating. For a firm connection, crimp / solder a suitable pin type of copper terminal on the wire end to be connected to the power supply. For convenience, a pair of terminals has been provided for crimping / soldering to the wire end.
OPERATION
-Ensure that the on / off switch on the power supply is switched off and it is un-plugged from the AC outlet
-Switch off the 12 V load to be connected to the power supply. Connect the positive input wire of the load to the RED (Positive) terminal of the power supply and the negative input wire of the load to the BLACK (Negative) terminal of the power supply. Ensure that the connections are secure and tight
-Plug the power supply into the AC outlet. Press the On / Off switch of the power supply to the On position and check that the switch is illuminated indicating availability of the AC input power. If the On / Off switch is not illuminated, recheck the AC input connection, AC outlet and the fuse inside the power supply.
-The voltmeter on SEC-1235M will read 13.8 V.
-Now switch on the DC load
-The ammeter on SEC-1235M will indicate the current drawn by the load
-Ensure that the continuous load is limited to 30 A
COOLING FAN CONTROL / THERMAL PROTECTION
WARNING! Operate the unit in a well ventilated, open and cool area. Do not block the openings at the fan discharge on the bottom of the unit and the suction openings on the sides.
The units are cooled by convection and by forced air cooling. A temperature controlled fan has been provided to improve cooling at higher loads and at higher ambient temperatures. The switching on of the fan is controlled by a sensor mounted on the power transformer. The fan will be switched on when the temperature of the sensor reaches 60° C +/- 5° C. The fan will be automatically switched off when the sensor cools down to 50° C +/- 5° C. Thus, at lower loads or during lower ambient temperatures, the fan may remain switched off.
An additional protection is provided to shut down the power supply in case the fan fails or if the air flow is blocked or if the ambient temperature is very high. A second temperature sensor is also mounted on the power transformer and will activate at 105° C +/- 5° C and shut down the output of the power supply. After the power supply cools down to 95° C +/- 5° C, the temperature sensor will deactivate and the power supply will resume operation automatically
4.
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