Check Operation Of Oven Heaters - Siemens Maxum Edition II Installation Manual

9. Check sample line(s) by blocking return or vent line and pressuring with air or non-
combustible and non-toxic gas to check for sample line leaks in the oven.
10.Uncap all vents and reestablish utility gas flows.
4.6

Check Operation of Oven Heaters

For Air Bath heaters (including PTGC) perform the following procedure: Note that on PTGC
units, it is recommended to have carrier flow thru columns during this test.
1. Turn heater circuit off by setting oven air regulator below 5 psig. This procedure uses the
PECM status LEDs. See Appendix A - PECM LED Interpretation (Page 49).
2. Through the front panel screen, observe the oven temperature and set point temperature.
3. Cool oven down, approximately 20 to 40 degrees below set point.
4. Increase oven air regulator slowly until the oven pressure switch triggers the heater circuit
(between 6 and 9 psig), this is indicated when the top LED lights (green).
5. Note: a unit with a vortex cooling device will have its regulator setting significantly above
this. Utilize the "Heater Air" gauge reading for this check.
6. Observe when the heater circuit goes into temp limit. This is indicated when the third LED
lights (yellow).
7. On the PECM, press and hold the appropriate oven temp test button down (this may take a
few minutes).
Figure 4-4
Installation Manual
Installation Manual, 12/2019, 2000595 Rev 1
CAUTION
Verify operation of the Air Pressure Switch. A malfunctioning Air Pressure Switch will
cause overheating and possible equipment damage.
Turning off the air should cause the air pressure switch on the right side of the electronics
enclosure to open and shut off the oven heating. If the oven continues to heat without air,
turn the power off immediately. Do not continue with the rest of the procedures until the
heater circuit checks out.
PECM Overtemperature Test Switches
Initial Startup Procedures
4.6 Check Operation of Oven Heaters
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