Dialarc HF-p, post flow timer question

[Cyclone]

Hi, I'm new to this great forum, just got a Dialarc HF-p (HK234701). Everything works except the post flow timer. When I finish my weld and stop the arc, I can see arcing in the timer, and the gas and water valves(not using water valve) rattle/buzz. No post flow gas comes out of the torch. I see miller4less has a relacement timer ($218.). Does anyone know if I can wire in a solid state off-delay timer similar to this , my budget is shot from buying the welder. Any ideas would be great. Thx.

[cruizer]

Do you really need it? Personally i'd just take it out of the circuit.

[duaneb55]

Do you really need it?

Yes, unless he doesn't care about contaminated tungsten and weld due to no post arc cooling/shielding gas flow.

[duaneb55]

Does anyone know if I can wire in a solid state off-delay timer similar to this

Or one such as these http://www.mcmaster.com/#repeat-cycle-timers/=gvqo0y (panel mounts about half way down the page) with a higher amperage rating. Technical term, "delay on make".

[Cyclone]

Or one such as these http://www.mcmaster.com/#repeat-cycle-timers/=gvqo0y (panel mounts about half way down the page) with a higher amperage rating. Technical term, "delay on make".

Shouldn't this post flow require a "delay on break" style? Arc stops, foot off pedal...time delay starts to keep gas valve open for desired anount of time?


Thx duaneb55, any chance you could draw up a wiring diagram to use one of these?

[cruizer]

Yes, unless he doesn't care about contaminated tungsten and weld due to no post arc cooling/shielding gas flow.

I the shops I see most operators have turned the post flow either to 1/2 second or off. When they are done a weld, I don't see them sitting at the end of the weld for 5-10 seconds waiting for the tungsten to cool down. they release the pedal and move on to the next weld, or merely lay the torch down.

[duaneb55]

Shouldn't this post flow require a "delay on break" style? Arc stops, foot off pedal...time delay starts to keep gas valve open for desired anount of time?

The "make" or "break" is the timer start signal. On the Dialarc HF the timer is activated (started) by the closing of the NC contacts of control relay CR2. Therefore the "delay" timer is started upon the "make" signal from the NC contacts of de-energized CR2.

A look at the machine circuit diagram should clarify.

Page 13.
http://www.millerwelds.com/om/o315e_mil.pdf

[duaneb55]

This http://www.alliedelec.com/search/pro...x?SKU=70172628 would be a better choice as it's a multi-function unit and lets you pick the delay mode best suited for the application and control configuration.

Download the data sheet for a full description of modes operation and control circuits.

A full selection of accessories (panel mounts, bases, latches, adapter plugs, etc.) are available as well.

[Cyclone]

Thx Duane,
Sounds good, I'll let you know how it works. While testing and making my diagram, I discovered that the 120v signal is actually 144v at the timer (TD1) and the front panel receptacle. Do you think that's acceptable or is there something amis with the 115v transformer (T2)?

[duaneb55]

Thx Duane,
Sounds good, I'll let you know how it works. While testing and making my diagram, I discovered that the 120v signal is actually 144v at the timer (TD1) and the front panel receptacle. Do you think that's acceptable or is there something amis with the 115v transformer (T2)?

Sounds as if the primary input power jumpers are set up for 200VAC input and the machine is connected to 230V.