Manestro wrote

1) Can I  use the same utp cable (the cable that is used by the existed AP ) and the same power supply (24V 0,5Amp-PoE PSU)  to power the second AP  by using the LAN1 port or I have to install separate cable and PSU? 

2) Wich is the best -way - operation mode to install the second AP , 

3) Any suggetion to solve it ?

1) Theoretically yes, but you would need a more powerful PoE adapter.

According to the specs, CPE520 consumes up to 14 watts. The PoE adapter supplies up to 0.6A @24 volts, that's 14.4 watts. You could use the PoE passthrough function with a separate cable from LAN 1 port of the existing CPE520 to the new one, but you would need a PoE adapter which can supply at least 1.5A @24 volts to power both CPEs.

With CPE510 v1.1 I did use such a setup successfully, but those models consume max 10.5 watts and their PoE adapter supplys 24 watts (1.5A), that's enough for two CPEs. Ironically, CPE510 v2 and newer don't have a second LAN port anymore, so no PoE passthrough is possible with those devices. I don't know whether CPE520 still has a second port.

But using the same cable from the PoE adapter is not possible.

2) Doesn't matter as long as one CPE operates in AP mode and the remote one operates in Client mode. The only difference is: an AP can serve more clients while a client needs to connect to exactly one AP.

3) Alternative would be a single WBS510 with a sector antenna TL-ANT5819MS which has 120° (6dB) resp. 90° (3dB) beam width. But I would prefer the solution with two separate CPE520 since this increases the throughput you can achieve.

Note that CPE520 and WBS510 are at end of life already.

Manestro wrote

But I thing that the output voltage  of TL-SG1008P is regulated according to device that plug in to it. Is that correct?

No, don't do this, it won't work! TL-SG1008P uses PoE according to IEEE 802.3af, while Pharos devices require passive PoE (24V). You need a 24V PoE adapter capable of delivering 1.5A. The PoE adapter must use pins 4 & 5 of the Ethernet cable for +24V and pins 7 & 8 for GND.

Passive PoE is not compatible with 802.3af PoE.