CHAPTER 2: INSTALLATION
MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
2-4
990-280
F FOOTSWITCH: This receptacle is used to connect either a 1-level or 2-level Unitek Peco
footswitch. Footswitches are only used with air or electrically actuated weld heads.
G MECHANICAL FIRING SWITCH: 4-foot cable is used to connect the 250DP to the force firing
switch in all Unitek Peco weld heads and hand-pieces.
H POWER CABLE: 5-foot cable is terminated with the appropriate 115 or 230 volt plug. The
standard plug for the 115 VAC power supply a NEMA 5-15P rated for 15 amps.
I
CB1, CB2: Circuit breakers are used to protect the incoming power line.
J COVER PLATE : Used when the Weld Sentry option is not installed.
Firing Switch Connections
Connect the weld head or hand-piece to the appropriate firing cable or switch located on the rear panel of
the 250DP.
Mechanical Firing Switch
Unitek Peco weld heads and hand-pieces are force fired and have two-pin firing switch connectors
which can be connected directly to the mating connector of the MECHANICAL FIRING SWITCH
located on the rear panel of the 250DP.
Users of manually actuated weld heads which do not have force firing switches must connect the two
pins in the mechanical firing switch to an external switch in order to initiate the 250DP.
Air actuated weld heads which do not have force firing switches rely on the squeeze time to ensure that
the weld head has time to close and apply the proper force to the workpieces. Use the squeeze time
option and select NO FIRING SWITCH from the Options Menu (refer to Chapter 3).
Optical Firing Switch
Users of weld heads with pressure switches using a 3-wire switch or an optical device should use the
OPTICAL FIRING SWITCH receptacle located on the rear panel of the 250DP (refer to Appendix A
under
Initiation Switch).
3-Wire Firing Switches
Users of weld heads with single pole, double throw, 3-wire pressure switches should also use the
OPTICAL FIRING SWITCH connector. The 250DP will automatically detect that the system is using a
3-wire switch if Pin 2 is low at power-up.