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Date: 20 Feb 2007 05:47:31
From:
Subject: Silvia PID temp control problems
For one year after PIDing Silvia(Murph's) all was well. Suddenly I
could not control the temperature from rising to steaming levels. I
rechecked the tuning of the PID(Fuji PXR3), replaced the thermocouple
and checked the wiring. All was OK. I disconnected the PID and
Silvia seems to work perfectly. Could the relay be the culprit or is
it the PID itself? I'd appreciate suggestions. Thanks in advance





 
Date: 20 Feb 2007 07:18:34
From: daveb
Subject: Re: Silvia PID temp control problems
On Feb 20, 8:47 am, esto...@earthlink.net wrote:
> For one year after PIDing Silvia(Murph's) all was well. Suddenly I
> could not control the temperature from rising to steaming levels. I
> rechecked the tuning of the PID(Fuji PXR3), replaced the thermocouple
> and checked the wiring. All was OK. I disconnected the PID and
> Silvia seems to work perfectly. Could the relay be the culprit or is
> it the PID itself? I'd appreciate suggestions. Thanks in advance

Does the boiler lite come on INSTANTLY when you turn on the power?
(steam switch off)

then it is the SSR. (internally shorted)

the controller does a brief 'self-test' before it does anything
about the temperature

dave
www.hitechespresso.com
Saeco / Gaggia service SE



  
Date: 21 Feb 2007 00:31:39
From: jggall01
Subject: Re: Silvia PID temp control problems
On 20 Feb 2007 07:18:34 -0800, "daveb" <davebobblane@gmail.com > wrote:


>Does the boiler lite come on INSTANTLY when you turn on the power?
>(steam switch off)
>
>then it is the SSR. (internally shorted)

I like that ;-) Much easier diagnosis.

The only time I experienced those symptoms turned out to be an
internal short in a controller. It was sending around 10VDC to the
SSR all the time.

Jim


 
Date: 20 Feb 2007 06:17:40
From: jggall01
Subject: Re: Silvia PID temp control problems
estokar@earthlink.net wrote:
> For one year after PIDing Silvia(Murph's) all was well. Suddenly I
> could not control the temperature from rising to steaming levels. I
> rechecked the tuning of the PID(Fuji PXR3), replaced the thermocouple
> and checked the wiring. All was OK. I disconnected the PID and
> Silvia seems to work perfectly. Could the relay be the culprit or is
> it the PID itself? I'd appreciate suggestions. Thanks in advance

First, check that the LED indicator on the controller for OT1 cycles
off as the temp approaches setpoint.

Next, confirm (i.e. measure) that the off-state voltage output from
the controller OT1 is 0VDC (or at least less than 1.5VDC).

If it is neither of these, then your SSR has failed (sounds likely)
and will need to be replaced.

Jim