PID controller question?

[Deecoat]

Hello All,
I'm in the process wiring my oven and was wanting to ask a question abot wiring my temp. controller. I purchased a TC-408 PID controller from (auily) on ebay. I recieved a manual with the controller but can't seem to understand the part on J1/J2 alarm wiring.I am using a relay contactor instead of an SSR. Do I need to use these? Has anyone used this same controller? Here is how it says it should be wired:


Terminals:
(1) & (2) Power
(3) shows an jumper over to (4)
(4) & (5) J1 Power (Alarm)
(6) & (7) SSR IN/OUT Power (I assume this goes in/out to the relay contactor)
(9) & (10) Thermocouple
(13) & (14) J2 Power (alarm)

The manual also states:
Set controller to (0) Relay J1,J2 as alarm output;SSR disabled. Can be used for ON/OFF control.
Set controller to (1) Relay J1 as alarm output.J2 as PID controlled relay contact output.SSR out put disabled.
Set controller to (2) J,J2 as alarm output;SSR PID controlled with 12v output.
^
( And yes it did only have a (J) in this comment)

Anyone able to explain this because I maybe making this to complicated for myself.

Thank You!
Dee

[ed_denu]

Dee, This is the same controller I use. I do think you are making it more complicated than it needs to be.

Are you looking to use the high/low alarm contacts? If not, just ignore these settings and contacts. The PID will maintain the temperature set point so I chose not to have alarms sound for high and low temperatures.

Terminals 1 & 2 get the input power. Either 120 vac or 240 vac.

9 & 10 get the thermocoupler connections

6 & 7 are the dc voltage output connections to drive the SSR or contactor. This is the area you need to check closely. This PID outputs 8 VDC with a 40ma max load. Is the contactor you are planning to use capable of using an 8 VDC input voltage? Also check that it doesn't consume more than 40ma.

Is the contactor you are going to use a solid state device or mechanical? Most solid state contactors are really just heavy duty versions of SSR's which is fine. Once you have everything wired, follow the auto tuning instructions in #5. This allows the PID to automatically set parameters based on conditions within your oven.

If you are using a mechanical contactor you will find with auto tuning that the PID cycles the relay on and off frequently when temperatures approach the set point . This can be hard on mechanical contactors so set the 'ot - cycle rate' much higher.

[Deecoat]

Thanks for responding ed_denu!

The contactor I'm using is an Cutler-Hammer C25BN240A.

http://www.famousparts.com/c25bnf240aco.html

It does not say anything on the box about mA.
Any insight would be great.

Thanks again!

Dee

[ed_denu]

Forget my previous comments as it looks like you are going about your setup a little differently than I did. I used the 6 & 7 contacts to drive a DC input SSR.

If you want to use a 120 VAC contactor such as the C25BN240A then you cannot use the SSR outputs 6 & 7.

As I stated I didn't use this type setup but the instructions (somewhat vague) seem to state that if you set 'outy' to '1' then the SSR outputs are disabled and the J2 contacts can be used to drive a relay/contactor(120 VAC).

If you want to test this I would carefully apply power to the PID, set 'outy' to '1' and meter the J2,(13 & 14) contacts to see if they are outputing 120 VAC. If so then you would use the J2 contacts to drive the contactor.

Another thing I would watch is to not use the auto tuning function. The reason I caution about this is your contactor is mechanical. So you need to change the 'ot' setting to something much larger than the default 2 seconds. This is because as the PID senses temperature nearing the set point if cycles the relay on and off rather quickly. Not a good thing for a mechanical device.

Maybe someone else has experience using this type setup?