RTCA/DO-160D, section 22

[dho]

anyone know the way of this test for
it is a pressure switch to monitor the hydraulic pressure. (like your home well water pump switch.) It is just a pair of on-off contacts. In old days, +28 VDC in, thru the switch out to the lamp, then go back to -28 VDC. (nowadays, maybe lower voltage and mA current to PC.)
How to test this PRESSURE SWITCH per RTCA/160D, section 22, waveform 3, table 22-3 cable bundle, level 4, 1500 V and 300A?
Thanks

 

[IRstuff]

?? aren't you supposed to test for damage or false signals?

"These test methods and procedures apply idealized wavefmms to verify the capability of equipment to withstand effects of lightning induced electrical transients. The criteria for equipment performance in the presence of lightning transients shall be defined in the applicable equipment specification."

TTFN
I can do absolutely anything. I'm an expert!
faq731-376 forum1529

 

[dho]

the WHOLE requirement

"4.4.4.1. Indirect Lightning Effects Testing
The Indirect Effects testing shall be performed per DO-160D Section 22 using Waveform 3, Table 22-3 cable bundles, Level 4, 1500 Volts or 300 Amperes."

thanks.

 

[IRstuff]

No, the whole requirement is the entire document, the testing cited has to be in the context of what might be at the beginning of the environmental testing section. Since your cited test doesn't distinguish, "perform during", "perform after", or "survive", then your system must meet its performance requirements specified earlier in your document during and after such a test.

TTFN
I can do absolutely anything. I'm an expert!
faq731-376 forum1529

 

[dho]

ok, let's say the pressure switch actuates at 100 psi, and close a circuit of 1 amp 28 VDC. with 100 megohm insulation resistance. we will verify that after the test.
BUT, how we physically do this section 22 test? you definitely will not flow 300 amp thru the switch.
thanks.

 

[IRstuff]

Did you look at figure 22-7? Based on that, you ought not injecting that much current into the switch, because it's all common-mode. Moreover, if there is an issue, then you should shield the wire bundle.

TTFN
I can do absolutely anything. I'm an expert!
faq731-376 forum1529

 

[dho]

160D, fig 22-7, LISN input impedance characteristics.
says not much to me with my little knowledge of it.
if i understand correctly, as an airplane hit by a lightning, the current goes from the cloud through the plane's skin and finally reaches ground. (or another cloud, or another part of the cloud.)
any thing inside the plane will subject to some V/A BY the induction.
then the V/A magnitude all depend upon how the equipment is located against the plane skin.
the para 4.4.4.1 tells nothing. the 1500V and 300A are the magnitude of the lightning, so test can not be performed to the pressure switch ALONE.
help?

 

[IRstuff]

sorry, should have Figure 22-17 Typical Cable Bundle Test Setup. The voltages and currents are only truly available in the calibration configuration.

TTFN
I can do absolutely anything. I'm an expert!
faq731-376 forum1529