time clock with an asco

[whals]

A question about a time clock and a asco

I have a tork dgu100 time clock that is going to a asco 918, and we also have a over ride switch. I got the switch to work the lights with the coil closed. After calling tork they told me it can't be done bocause the time clock is not a momentary clock which is dgum100. Call asco and they say it can be done with an accessory 47 on the asco. Does anybody know how the 47 works? I looked for a good diagram but couldn't find one.
thanks for the help

 

[gar]

100908-2016 EST

I went looking for something on the theory of operation of this switch. Very bad literature and discussion.

I finally found something with a wiring diagram. It appears this switch is a multipole contactor with a single coil used to step a mechanical system from open to closed to open.

The logic of the circuit is that a pair of contacts, one NO and one NC are connected to the coil. These contacts effectively indicate the state of the contactor. The control input terminal to cause the contactor to transfer to the contactor closed state is thru a contact that is closed when the contactor is open. Applying a control signal, voltage, between this terminal and to the other end of the coil energizes the coil causing the contactor to step to closed. In turn the control signal to the coil is removed from the coil.

To step the contactor again, meaning to off, a control signal must be applied to the other input control terminal.

Thus, a SPDT switch can control this contactor. If you want multiple control points, then it is necessary that the SPDT paralled control switches be momentary action spring return to center switches.

To work with additional switches to control the lights you need short pulse outputs from the time switch and spring return to center SPDT switches for your manual switches. You can make the time clock put out short pulses, maybe 30 to 60 milliseconds, with two time delay devices used to generate the pulses.

Your problem is typical of a product that has an inadequate discussion of its theory of operation. If you know how something works, then you can better troubleshoot problems. I suspect the 47 accessory generates the pulses from two steady inputs from their leading edges. This would be described as an edge triggered pulse generator.

.

 

[whals]

Thanks for taking the time and looking that up

 

[infinity]

Accesory 47 is for two wire control. This would allow you to turn the contactor on/off with a single pole switch. Multiple switches and a time clock would require momentary contact switching. If your time clock has ON and OFF pulses you don't need Accessory 47 since you could wire this with a 3-wire control system.

 

[mcelweec@gmail.com]

Check out the tork "smc 3d" when given power it sends a pulse on the NO and when power is removed it sends a pulse on the NC.

 

[steve66]

I was just looking up ASCO lighting controls this morning:

http://www.emersonnetworkpower.com/...CO918LightingContactorsforBranchCircuits.aspx

Look under the options tab.

STeve

 

[brian john]

The 918 is a mechanically held contactor you need power to open and to close it, use an auxiliary relay with NO/NC save money on the accessory.

 

[gar]

100917-2152 EST

brian:

Can you explain what you mean.

If you want more than one switch location from where the contactor is controlled, then the control signals need to pulse the contactor coil.

Inherently the contactor self pulses itself, but you can not maintain one or both input signals or there will be an oscillation between on and off. or vice versa, or continuous oscillation, when another control signal occurs on the opposite input.

.

 

[infinity]

100917-2152 EST

brian:

Can you explain what you mean.

If you want more than one switch location from where the contactor is controlled, then the control signals need to pulse the contactor coil.

Inherently the contactor self pulses itself, but you can not maintain one or both input signals or there will be an oscillation between on and off. or vice versa, or continuous oscillation, when another control signal occurs on the opposite input.

.

Actually you can maintain power on either the latch or unlatch terminal indefinitely just not both as you've mentioned. The ASCO has built in auxiliary switches to allow the power to be maintained. This would allow you to operate the ASCO with a single standard three way switch. Accessory 47 allow you to use a regular old single pole switch for two wire control.

 

[iwire]

Actually you can maintain power on either the latch or unlatch terminal indefinitely just not both as you've mentioned. The ASCO has built in auxiliary switches to allow the power to be maintained. This would allow you to operate the ASCO with a single standard three way switch. Accessory 47 allow you to use a regular old single pole switch for two wire control.

I agree with Rob.

 

[gar]

100918-0803 EST

What I have tried to point out is that you can not control this contactor from multiple switches unless the control signals are externally pulsed. Yes, the contactor does internally create pulses to the coil, but that alone it not sufficient to allow multiple external control switches.

You can not take two SPDT switches that are not spring return to center, parallel these, and use these to control the contactor.

Whereas any number of SPDT switches with spring return to center can be paralleled and control the contactor.

Note: the first post indicated an over-ride switch. The details were not provided, but this implies that there are multiple control points, meaning that at least one of the control lines will have a second switch in parallel with one of the timer switches.

.

 

[infinity]

100918-0803 EST

What I have tried to point out is that you can not control this contactor from multiple switches unless the control signals are externally pulsed. Yes, the contactor does internally create pulses to the coil, but that alone it not sufficient to allow multiple external control switches.

You can not take two SPDT switches that are not spring return to center, parallel these, and use these to control the contactor.

Whereas any number of SPDT switches with spring return to center can be paralleled and control the contactor.

Note: the first post indicated an over-ride switch. The details were not provided, but this implies that there are multiple control points, meaning that at least one of the control lines will have a second switch in parallel with one of the timer switches.

.

Yes I agree. The override switch would typically be used to override the time clock. As Gar has pointed out the only workable switching system is a momentary one.