Closes #2231

The "load" component is called "t", use that.

chapters/classes.tex

@@ -1195,8 +1195,8 @@ \section{Balanced Models}\doublelabel{balanced-models}
 \emph{Local equations}: 
 \begin{eqnarray*} \text{p.v} &=& \text{t.p.v};\\
 0 &=& \text{p.i}-\text{t.p.i};\\
-\text{c.p.v} &=& \text{load.n.v};\\
-0 &=& \text{c.p.i}+\text{load.n.i};\\
+\text{c.p.v} &=& \text{t.n.v};\\
+0 &=& \text{c.p.i}+\text{t.n.i};\\
 \text{n.v} &=& \text{c.n.v};\\
 0 &=& \text{n.i}-\text{c.n.i};
 \end{eqnarray*}