Page 1
UPGRADE INSTRUCTIONS
HT400 FLOW SWITCHES
Purpose
The HT400 flow switch upgrade instructions provide the necessary information to allow the
removal of the existing flow switches and replacing them with the Kobold flow switch manifold
subassembly.
Customer Supplied Tools
Drill
3/16" (0.187)/4.762mm drill bit
Straight blade screwdriver
7/16" (11.11 mm) open-end wrench
9/16" (14.29 mm) open-end wrench
11/16" (17.46 mm) open-end wrench
1/4" (6.35 mm) hex wrench
Flow Switch Assembly Upgrade Kit (# 028484)
Part No. Description Qty.
029546 Kobold flow switch manifold SA 1
005139 Flow switch, 0.25 GPM
005140 Flow switch, 1.20 GPM
004456 Flow switch manifold
074005 Cable Tie 5
075040 M/S:10-32 X 5/8 3
075186 Lock washer:#10 Intl-T 3
Procedure
Remove Existing Flow Switches
To remove the existing flow switches, refer to the following procedure and the figures called out
from the HT400 Plasma Arc Cutting System Instruction Manual IM-54 (P/N 800540).
1. Shut the power supply down at the front panel and turn off power at the disconnect box.
Disconnect the gas supply to the power supply. Disconnect the water supply to the power
supply.
2. Remove the top cover and the left side cover to access the flow switches on the center wall.
Refer to Figure 38.
3. Remove the tyraps from around the flow switches leads which are connected to the terminal
strip located on the opposite side of the wall..
4. Disconnect the 4 switch leads (red) from the terminal strip. These leads are marked 4 (2), 5,
and 6.
5. Disconnect the input water hose (left side) from flow switch 2FLS (005053). Refer to Figure
38. Disconnect the other end of the hose from the water manifold (top hose) at rear panel.
Refer to Figure 39. Remove the plug from the upgrade kit and screw into the manifold where
the hose was disconnected. Refer to Figure 1 in this upgrade instruction.
