Si85c-Maxum-Heater-Circuit_Rev1

SIEMENS
Siemens Industry, Inc.
Technical Support Information No. 85c
November 2007
Process Analytics – USA
Customer1Focus
Page 1 of 6
Maxum II Heater AC Circuit
MAXUM II is available with
•
•
air bath ovens, in a single isothermal, dual split-oven isothermal and dual oven in a
isothermal/programmable temperature version.
airless ovens, in a dual isothermal version.
Whereas TCDs are mounted inside the ovens, heated detectors such as FID, FPD or specific detectors such as
PDHID are mounted on top of each oven independently. This provides additional oven and application flexibility as
well as simplified maintenance.
Siemens Industry, Inc. - Process Analytics
Phone 713-939-7400 Fax 713-939-9050 Email [email protected]
All information provided on this page is for informative purposes only and is not binding. Siemens Industry, Inc. reserves the right to change
information on this page at any time. Siemens Industry, Inc. will not accept liability for or guarantee the accuracy of the information contained
herein.
SIEMENS
Siemens Industry, Inc.
Technical Support Information No. 85c
November 2007
Process Analytics – USA
Customer1Focus
Page 2 of 6
The single air bath oven has a size of about 580mm x 370mm x 280mm / 23" x x14.5" x 11" (wxhxd).
The dual air bath ovens have each the size of about 270mm x 370mm x 280mm / 9" x 14.5" x 11" (wxhxd).
The dual airless ovens have each the size of about 225mm x 340mm x 250mm (8.8"x13.5"x10") and has been
added to MAXUM in 2003. Initially, when integrating the features of the European Siemens Process GC PGC302
into MAXUM, the significant preference of airless ovens of European users was the motivation. However, in the
mean time the airless oven configuration is gaining fast followers in North America as well.
Both ovens have about the same oven stability.
There are a number of differentiators between air bath and airless ovens:
1: COST OF AIR
Cost of instrument air can represent a significant operational cost factors.
Typical cost of air over the life time (15 years) of an analyzer is shown in the following graph.
The cost of air includes oven air as well as electronic purge air for airless oven MAXUM, air bath oven MAXUM
and air bath oven of another Process GC manufacturer.
Siemens Industry, Inc. - Process Analytics
Phone 713-939-7400 Fax 713-939-9050 Email [email protected]
All information provided on this page is for informative purposes only and is not binding. Siemens Industry, Inc. reserves the right to change
information on this page at any time. Siemens Industry, Inc. will not accept liability for or guarantee the accuracy of the information contained
herein.
SIEMENS
Siemens Industry, Inc.
Technical Support Information No. 85c
November 2007
Process Analytics – USA
Customer1Focus
Page 3 of 6
2. MAXIMUM OVEN TEMPERATURE
Air bath oven temperature range is 5 C to 225 C and 5 to 260 C for the airless oven. The temperature programmable
oven temperature limit is 320 C.
The temperature difference between split ovens is more than 100 C. For example 60 C in one and 160 C in the other.
However, that difference becomes smaller if one oven is running close to ambient at 45 C without active cooling.
An electrically heated coil is used to heat up the air used for the air bath oven. Because of the surface temperature
limitations (T-Rating) for an electrical hazardous area and because of the poor thermal properties of air, the
maximum oven temperature possible for a given T-Rating is low. For example, the maximum oven temperature than
can be reached for a:
T3 area (200 C) is 140 C,
T2 area (300 C) is about 200C
On the other hand, an airless oven is heated by heating cartridges located inside the cast alloy oven casing. With
much better conductivity, the maximum oven temperature for a:
T3 area (200 C) is about 175 C.
T2 area (300 C) is about 260 C.
3. HEAT-UP RATE
Although one might think that an air bath oven is faster heating up, this is not true in general and is strongly
dependent on the T-rating. For example
To 60 C 15 minutes for air bath and 30 minutes for airless (T3)
- ambient to 70 C takes 70 minutes for air bath and 35 minutes for airless (T4 area)
- ambient to 70 C takes 10 min for air bath and 35 minutes for airless (T3 area)
- ambient to 80 C takes 20 minutes for air bath and 40 minutes for airless (T3 area)
- ambient to 90 C takes 45 min for air bath 50 min for airless (T3)
- ambient to 120 C not possible with and air bath for T3 rating
- ambient to 120 C takes 40 minutes for air bath and 65 minutes for airless (T2-A area)
- ambient to 160 C takes 90 min for air bath and 90 min for airless (T2A)
The temperature programmable oven is located inside one of the split isothermal oven compartments. The
temperature programmable oven compartment is independently heated with an air bath heater. Heat-up and cool
down rates depend on the temperature of the isothermal oven. The heat up rate is 60-80 C/min at the lower
temperature range.
The average heat-up rate up to 220 C is exceeding 20 C/min, up to 320 C it is exceeding 15 C/min. Possible heat-up
rates are T-rating dependent.
The cool down speed is often accelerated by installing a Vortex cooler into the air supply line.
The design of the temperature programmable enclosure provides heat along the column outlet to the detector base in
order to prevent cold spots.
Siemens Industry, Inc. - Process Analytics Phone 713-939-7400 Fax 713-939-9050 Email [email protected]
All information provided on this page is for informative purposes only and is not binding. Siemens Industry, Inc. reserves the right to change
information on this page at any time. Siemens Industry, Inc. will not accept liability for or guarantee the accuracy of the information contained
herein.
SIEMENS
Siemens Industry, Inc.
Technical Support Information No. 85c
November 2007
Process Analytics – USA
Customer1Focus
Page 4 of 6
4. OVEN CONFIGURATION
Airless ovens can accommodate 3 externally mounted (top of the oven), independently heated detectors such as FID,
FPD or specific detectors. In addition 3 dual (total of 6) TCDs can be mounted inside the large air bath oven.
A split air bath oven can accommodate 2 independently heated detectors on top of the oven and additionally in each
oven a dual TCD (total of 4).
In addition to each externally mounted FID, a Methanator can be mounted next to it.
The large air bath oven can accommodate six column trains and still be accessible for maintenance. Eight column
trains can be accommodated in total but this generates a full oven.
A dual air bath or dual airless oven accommodates 2 column trains with up to 3 valves comfortably.
The single or dual air bath oven has a single large door whereas the dual airless oven has individual oven doors.
Individual oven doors permit the maintenance on one oven with the second oven on-line analyzing.
5. POWER REQUIRMENTS
The majority of the power is typically consumed by the analyzer oven.
Power requirements as specified:
Single Oven air bath: max. 1840 VA
Dual air bath (2 x isothermal): 2x1400 VA (one for each oven)
Dual air bath (temperature programmable / isothermal): 2x1400 VA
Dual Airless: (2 x isothermal) is max about 1840 VA.
6. COMMENT
In an enclosed shelter or laboratory, the airless analyzer ovens are substantially quieter compared to air bath ovens.
The air bath oven air should be vented outside the shelters in order to reduce air conditioning load on the shelter.
The MAXUM electronics consumes about 400 VA which is dissipated into the shelter. An airless oven typically
consumes about 300-400 VA and will dissipate into the shelter. The air bath oven consumes at least twice as much.
The majority of the hot air can be vented to the outside of the shelter.
As a side note, the Thermistor TCD can be converted to a Filament TCD. Same detector block, although the DPM
has to be changed.
Siemens Industry, Inc. - Process Analytics
Phone 713-939-7400 Fax 713-939-9050 Email [email protected]
All information provided on this page is for informative purposes only and is not binding. Siemens Industry, Inc. reserves the right to change
information on this page at any time. Siemens Industry, Inc. will not accept liability for or guarantee the accuracy of the information contained
herein.
SIEMENS
Siemens Industry, Inc.
Technical Support Information No. 85c
November 2007
Process Analytics – USA
Customer1Focus
Page 5 of 6
7. HEATER AC CIRCUIT CHECK
Check the heater elements with an ohm meter to verify they are not shorted, shorted to ground or open.
1. Turn off the power to the analyzer, following normal shutdown procedures
2. Unplug the heater from the heater power cable at the blue connector.
3. Connect one lead of the ohm meter to the center pin (2) of the blue connector on the heater wires. Then connect
the other lead to one of the outside pins (1 or 3). The ohm meter should read approximately 18 ohms +/- 2.
4. With one lead of the ohm meter connected to the center pin (2), connect the other lead to the other outside pin (1
or 3). The ohm meter should read approximately 18 ohms +/- 2.
5. Replace the heater if ether element does not measure 18 ohms +/- 2.
An open resistance reading is the typical failure. Both elements must be functional for the heater circuit to work
properly. In a 115VAC configuration one element can be open and the heater will heat the analyzer with just one
element functioning. With just one element working the heater may not be able to reach the operating temperature or
it could take longer to reach temperature.
Several factors can cause a heater element to open. These include: particulates or moisture in the air, lack of
sufficient air volume to the analyzer, and excessive vibration. Heater elements can also be damaged if dropped or
exposed to excessive physical shock (such as hitting the heater with a hammer).
6. Check each pin to chassis ground to verify none of the wires or heater elements are shorted to the case ground.
Correct the problem or replace the heater if a short is detected.
115 VAC or 230 VAC
Verify the system is configured for the correct voltage level. The analyzer can be configured to operate at 115 VAC
or 230 VAC.
This includes using the correct adapter and installing the correct fuses in the Power Entry Control Module.
There are two adapters:
The 115 VAC Cable Adapter is SAA part number 2017595-001.
The 230 VAC Cable Adapter is SAA part number 2017595-002.
In the Maxum I the adapter connector is located in the floor of the electronics enclosure between the left and
center SNE locations.
In the Maxum II the adapter connector is located on the left side of the electronics enclosure behind the
detector mezzanine area. Remove the left side access panel to check or replace this adapter.
115 VAC Adapter Cable
The heater should be configured with the two elements in parallel when connected to 115 VAC service. The center
tap of the heater is connected to AC Neutral. The center tap is pin 2 of the blue heater connector. The end of each
element of the heater is connected to AC Hot, through the solid state relays. These are pins 1 and 3 of the blue heater
connector.
230 VAC Adapter Cable
The heater should be configured with the two elements in series when connected to 230 VAC service. The center tap
is left open.
One of the elements is connected to AC Neutral and the other is connected to AC Hot through the solid state relays.
These are respectively pins 3 and 1 of the blue heater connector.
Siemens Industry, Inc. - Process Analytics Phone 713-939-7400 Fax 713-939-9050 Email [email protected]
All information provided on this page is for informative purposes only and is not binding. Siemens Industry, Inc. reserves the right to change
information on this page at any time. Siemens Industry, Inc. will not accept liability for or guarantee the accuracy of the information contained
herein.
SIEMENS
Siemens Industry, Inc.
Technical Support Information No. 85c
November 2007
Process Analytics – USA
Customer1Focus
Page 6 of 6
Power Entry Control Module Fuses
The heater element can operate from either 115 VAC or 230 VAC power sources with a total power output capacity
of 1400 to 1500 watts. If the primary AC voltage is changed from 115 VAC to 230 VAC, the Power Entry Control
Module (PECM) AB1 and AB2 fuses must be changed. For 115 VAC power the fuses are rated at 16 amps. For 230
VAC, the in-line fuses must be changed to 10-amp rating. DO NOT use a 16-amp rated fuse for 230 VAC primary
AC power. Also note that the Power Supply Module 115/230 VAC switch must be set to the correct setting.
Siemens Industry, Inc. - Process Analytics
Phone 713-939-7400 Fax 713-939-9050 Email [email protected]
All information provided on this page is for informative purposes only and is not binding. Siemens Industry, Inc. reserves the right to change
information on this page at any time. Siemens Industry, Inc. will not accept liability for or guarantee the accuracy of the information contained
herein.