  EC 19529-4430 was identified as a helium-rich star in the Edinburgh-Cape
Survey of faint-blue objects and subsequently resolved as a metal-poor extreme
helium (EHe) star in the SALT survey of chemically-peculiar hot subdwarfs. This
paper presents a fine analysis of the SALT high-resolution spectrum. EC
19529-4430 has $T_{\rm eff} = 20\,700 \pm250$\,K, $\log g /{\rm cm\,s^{-2}} =
3.49\pm0.03$, and an overall metallicity some 1.3 dex below solar; surface
hydrogen is $\approx 0.5\%$ by number. The surface CNO ratio 1:100:8 implies
that the surface consists principally of CNO-processed helium and makes EC
19529-4430 the coolest known carbon-poor and nitrogen-rich EHe star. Metal-rich
analogues include V652 Her and GALEX J184559.8-413827. Kinematically, its
retrograde orbit indicates membership of the galactic halo. No pulsations were
detected in TESS photometry and there is no evidence for a binary companion. EC
19529-4430 most likely formed from the merging of two helium white dwarfs,
which themselves formed as a binary system some 11 Gyr ago.
