APPENDIX A: TECHNICAL SPECIFICATIONS
MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
990-280
A-9
Cool Time
Cool time is the time between welds. In the rollspot function, the electrodes are wheels. The cool time
and the rotational speed of the wheels determine the distance between welds. An air head will not open
until the footswitch is released. Cool time can be set between 0.00 and 9.99 seconds.
Hold Time
Hold time is the delay from the end of the weld pulse until the head valve opens. Hold time applies only
to an air head. The delay can be set from 0.00 to 9.99 seconds.
Footswitch Type
The 250DP requires the use of a 1-level or 2-level footswitch in order to control an air actuated weld head.
The 250DP will automatically detect whether a Unitek Peco 1-level or 2-level footswitch is connected to the
FOOTSWITCH connector located on the rear panel.
The 250DP assumes that a 1-level footswitch is used if the input to the 2nd level is continuously closed.
The 250DP determines whether it is connected to a 1-level or 2-level footswitch whenever it enters the RUN
state. The options menu can be used to override the automatic selection feature.
FOOTSWITCH Connector
The FOOTSWITCH connector is a 4-pin Amphenol 91-PC4F (Unitek Peco PN 550-006) that mates
with an Amphenol 91-MC4M (Unitek Peco PN 520-009). Connect Pin 2 to Pin 3 on a user supplied 1-
level footswitch. This connector is wired as follows:
Pin
Description
1
Chassis
Ground
2
Footswitch Level 1 or Single Level Footswitch
3
Footswitch
Level
2
4
Common