Your PJ will be wired the same as the street transformer, and is a center tapped winding. The center tap is the N, and the two hot winding's are your 120v just as you street one is.
So if you want 120v you can use L1 and N...... OR.... L2 and N.
If you want 240v you use L1 and L2, and ignore N.
So you can drive (theoretically) a single 10kw load@ 240v
Or, you can drive 2 seperate 5kw loads on L1,N for one, and L2 and N for the second load.
You cannot drive a single 10kw 120v load.... as you can only use a single winding for a single load.... and the transformer will be unbalanced, which will only upset the voltage set point I expect.. the winding you use will drop volts, and the unused winding will be over volt, but the over the 240v winding still 240 average.
The diagrams here will help
https://en.wikipedia.org/wiki/Split-phase_electric_powerSo long story short.... yes. use fig 1 on that link, that transformer is your street transformer, which is essentially exactly the same as your PJ transformer. V1 and V2 are your L1 and L2
You cannot connect L1 with L2 together as a parallel 120v winding expecting N to be the common neutral... it will simply short the full secondary. ... hence this warning "Note; Can Not L1+N+L2" which no one understands either,
Connection of any part of the supply should only be done at the distribution board itself, or you will create all kinds of bogies.... leave it all floating , and let the house take care of it.
PJ N to switchboard N,
PJ L1 to switchboard L1,
PJ L2 to switchboard L2, and
PJ E ( STUD) to buss bar in s/board.
................oztules