Samlex America SEC-1235M User Manual

SWITCH MODE DC POWER SUPPL Y

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 V AC 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 1 1
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 P ARTS 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.

NEVER OPERA TE THE UNITS IN PARALLEL

6)

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 SUPL Y FOR DIRECT CHARGING OF BA TTERY OR
DIRECT CONNECTION TO A BA TTERY FOR BA TTERY 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”

FEA TURES

- 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

OPERA TION FROM AC INPUT VOLT AGE OF 230 V AC

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

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

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.

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).

• For 120 VAC operation (pre-set condition), points "D" and "E" on the

• The fuse on the AC side for the preset input voltage of 120 VAC is

•The detachable power cord that is provided has an “IEC 320-13”

3.

CONNECTION AND 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 “OPERA TION FROM AC INPUT VOL T AGE 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

un-plugged from the AC outlet
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

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.

- Ensure that the on / off switch on the power supply is switched off and it is

- Switch off the 12 V load to be connected to the power supply. Connect the

- Plug the power supply into the AC outlet. Press the On / Off switch of the

- 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.