diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index f655f6301..f3469fb18 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -92,6 +92,7 @@ Change Log
 - [ADDED] support for unequal leakage resistance and reactance for HV and LV sides of a 2W-transformer
 - [ADDED] Add VSC element, dc buses, dc lines, and hybrid AC/DC power flow calculation
 - [CHANGED] accelerate _integrate_power_elements_connected_with_switch_buses() in get_equivalent()
+- [FIXED] index error during unbalanced powerflow if multiple external grids are present
 - [CHANGED] accelerate distributed slack power flow calculation by using sparse-aware operations in _subnetworks()
 - [CHANGED] Trafo Controllers can now be added to elements that are out of service, changed self.nothing_to_do()
 - [ADDED] Discrete shunt controller for local voltage regulation with shunt steps
diff --git a/pandapower/results_gen.py b/pandapower/results_gen.py
index 865efefcf..9851eeead 100644
--- a/pandapower/results_gen.py
+++ b/pandapower/results_gen.py
@@ -170,7 +170,7 @@ def _get_ext_grid_results_3ph(net, ppc0, ppc1, ppc2):
     eg_bus_idx_ppc = np.real(ppc1["gen"][eg_idx_ppc, GEN_BUS]).astype(np.int64)
     # read results from ppc for these buses
     V012 = np.array(np.zeros((3, n_res_eg)),dtype = np.complex128)
-    V012[:, eg_is_idx] = np.array([ppc["bus"][eg_bus_idx_ppc, VM] * ppc["bus"][eg_bus_idx_ppc, BASE_KV]
+    V012[:, eg_idx_ppc] = np.array([ppc["bus"][eg_bus_idx_ppc, VM] * ppc["bus"][eg_bus_idx_ppc, BASE_KV]
                                       * np.exp(1j * np.deg2rad(ppc["bus"][eg_bus_idx_ppc, VA]))
                                       for ppc in [ppc0, ppc1, ppc2]])