  We propose a quantum model of fermions simulating the electrical breakdown
process of dielectrics. The model consists of $M$ sites with $N$ fermion modes
per site, and has a conserved charge $Q$. It has an on-site chemical potential
$\mu$ with disorder $W$, and an interaction of strength $J$ restricting each
fermion to excite two more fermions when moving forward by one site. We show
the $N=3$ model with disorder $W=0$ show a Hilbert space fragmentation and is
exactly solvable except for very few Krylov subspaces. The analytical solution
shows that the $N=3$ model exhibits many-body localization (MBL) as
$M\rightarrow\infty$, which is stable against $W>0$ as our exact
diagonalization (ED) shows. At $N>3$, our ED suggests a MBL to quantum chaos
crossover at small $W$ as $M/N$ decreases across $1$, and persistent MBL at
large $W$. At $W=0$, an exactly solvable many-body scar flat band exists in
many charge $Q$ sectors, which has a nonzero measure in the thermodynamic
limit. We further calculate the time evolution of a fermion added to the
particle vacuum, which shows a breakdown (dielectric) phase when $\mu/J<1/2$
($\mu/J>1/2$) if $W\ll J$, and no breakdown if $W\gg J$.
