September 3rd, 2009
Affected components:
- 620429 Rosemount 400A Main Electronics Board
- 620433 Rosemount 400A Isolated 4-20 maDC board
Situation: The analyzer appears to operate normally (mostly anyway). U13 seems to get very hot (so does U4 [voltage output buffer amplifier]) and there is a 620433 (V/I option board) installed. Also, when attempting to light the analyzer, the analog display will overrange and remain overranged until the power is cycled on the analyzer (TP-5 will be saturated at about 13 vdc).
Problem: someone has employed the E1-E2 and E3-E4 jumpers and this is causing a nasty feedback loop that U13 is trying to compensate for. When the analyzer goes upscale (it always spikes during startup) this causes the analog signal to spike which, in turn, causes the 4-20 maDC card to spike. The 4-20 signal being fed back to U13 has now locked it railed high.
Resolution: remove the 4-20 maDC board or remove the E1-E2 and E3-E4 jumpers.
Other info: U12 & U13 & U4 are µA714 opamps (a.k.a., uA714); they can be replaced with OP07 or OP77 or OP177.
Posted in General - 400A hydrocarbon analyzer | No Comments »
September 2nd, 2009
Background: The 105% indication and reading is Rosemount’s way of showing an error message; it was presumed that everyone in the opacity business would recognize that there is no such thing as 105% opacity and that it would instantly mean ‘analyzer failure’ to anyone observing it on the monitor’s display. It was also an easy way to get the milliamp output signal to rail high at about 21 maDC.
Components affected: LCW (liquid crystal window), lamp (bulb), power supply (SLB, Stack LON Board), G-64 LON Board, interconnecting cabling, & temperature.
The fault alarm (105% opacity) can come from any of the following:
[1] failing bulb/lamp or lamp power supply
[2] failing LCWs or LCW power supply
– VLTH [volts too high]
– LMPF [lamp failure per software algorithm]
[3] loss of Eshelon communications (LON)
[4] failing wire harness (to lamp or LON communications)
[5] failed calibration
[6] corrupted software on the Stack LON Board
[7] failing detector board (±15 vdc power comes from the SLB)
But not:
[a] actual stack opacity conditions (high opacity)
[b] misalignment
[c] dust on barrier window and/or corner cube
[d] steam that has changed phase to vapor
Call us to help you diagnose this. Please provide the following:
- model number
- age of LCWs
- age of bulb/lamp
- reference voltages (8) (under Cal, Reference Voltages)
- current ‘run’ voltages (4) (under Data, Volts)
- temperature
Posted in Opacity Analyzers, Opacity Analyzers - Problems & Solutions | No Comments »
May 25th, 2009
Components affected: LCW, liquid crystal window, lamp, barrier window, alignment, bulb, & temperature.
High opacity can come from any of the following:
[1] actual stack opacity conditions
[2] misalignment
[3] failing bulb/lamp or lamp power supply
[4] failing LCWs or LCW power supply
[5] dust on barrier window and/or corner cube
[6] steam that has changed phase to vapor
Call us to help you diagnose this.
Please provide the following:
- model number
- age of LCWs
- age of bulb/lamp
- reference voltages (8)
- current ‘run’ voltages (4)
- temperature
Posted in Opacity Analyzers - Problems & Solutions | Comments Off
May 25th, 2009
Communication failures typically fall in to 2 categories:
[1] bad interconnecting wiring
[2] board faults
If you’re not using Belden 8162 or 8163, you run the risk of causing a communications problem that gets worse with time.
The CRU talks RS232 which then routes to a converter (RS232 to RS422) before the signal leaves the CRU. The transceiver receives the RS422 directly without a converter.
Here is the order of typical failures:
[1] RS232/RS422 converter in the CRU
[2] IO Plexor
[3] CPU board in the CRU
Call for more details.
Posted in Opacity Analyzers - Problems & Solutions | Comments Off
May 25th, 2009
Communication failures typically fall in to 2 categories:
[1] bad interconnecting wiring
[2] board faults
If you’re not using Belden 8162 or 8163, you run the risk of causing a communications problem that gets worse with time.
The LON originates on the Stack LON board AND the IG-1 serial gateway. If either board is faulted, unpowered, corrupted, blown power supply, or whatever then you’ll get COMM FAULTS.
Call for more details.
Posted in Opacity Analyzers - Problems & Solutions | Comments Off
May 22nd, 2009
RIGAS supports the entire Rosemount gas product line. In fact, the owner of RIGAS has been working with the Rosemount analyzers since 1984!
Remember: Boards are repairable …
… optics are repairable!!
Don’t throw those very expensive Rosemount boards away! 99.9% of the time they are repairable!!
We stock critical parts! We stock ‘obsolete’ parts! We fabricate parts (sometimes out of thin air, but we get the job done!!)!!
Call us: 877-616-0600
330-345-5264
330-345-5944 (fax)
Posted in General - Gas Analyzers | Comments Off
May 22nd, 2009
We have some great information about your OPM. If you’re a contract customer, this information is free, just call us. If you’re an internet surfer looking for free OPM information, please note that general information can be found in the product manual. We charge for superior technical expertise to help offset our website expense, telephone expense, labor overhead, insurance, and the list goes on. Thanks for your understanding.
RIGAS
330-345-5264 Local
877-616-0600 toll free
330-345-5944 Fax
Technical Information:
Posted in Technical Information | Comments Off
May 22nd, 2009
We have some great information about your NOx analyzer. If you’re a contract customer, this information is free, just call us. If you’re an internet surfer looking for free information, please note that general information can be found in the product manual. We charge for superior technical expertise to help offset our website expense, telephone expense, labor overhead, insurance, and the list goes on. Thanks for your understanding.
RIGAS
330-345-5264 Local
877-616-0600 toll free
330-345-5944 Fax
Posted in General - CLD | Comments Off
May 22nd, 2009
We have some great information about your PMD analyzer. If you’re a contract customer, this information is free, just call us. If you’re an internet surfer looking for free analyzer information, please note that general information can be found in the product manual. We charge for superior technical expertise to help offset our website expense, telephone expense, labor overhead, insurance, and the list goes on. Thanks for
your understanding.
RIGAS
330-345-5264 Local
877-616-0600 toll free
330-345-5944 Fax
Posted in Technical Information | Comments Off
May 22nd, 2009
We have some great information about your NDIR analyzer. If you’re a contract customer, this information is free, just call us. If you’re an internet surfer looking for free analyzer information, please note that general information can be found in the product manual. We charge for superior technical expertise to help offset our website expense, telephone expense, labor overhead, insurance, and the list goes on. Thanks for
your understanding.
RIGAS
330-345-5264 Local
877-616-0600 toll free
330-345-5944 Fax
Posted in General - NDIR | Comments Off
