diff --git a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/AbstractVoltageLevel.java b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/AbstractVoltageLevel.java
index 4a67bac2..1c33e787 100644
--- a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/AbstractVoltageLevel.java
+++ b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/AbstractVoltageLevel.java
@@ -71,7 +71,7 @@ public float getLowVoltageLimit() {
 
     @Override
     public VoltageLevel setLowVoltageLimit(float lowVoltageLimit) {
-        ValidationUtil.checkLowVoltageLimit(this, lowVoltageLimit);
+        ValidationUtil.checkVoltageLimits(this, lowVoltageLimit, highVoltageLimit);
         float oldValue = this.lowVoltageLimit;
         this.lowVoltageLimit = lowVoltageLimit;
         notifyUpdate("lowVoltageLimit", oldValue, lowVoltageLimit);
@@ -85,7 +85,7 @@ public float getHighVoltageLimit() {
 
     @Override
     public VoltageLevel setHighVoltageLimit(float highVoltageLimit) {
-        ValidationUtil.checkHighVoltageLimit(this, highVoltageLimit);
+        ValidationUtil.checkVoltageLimits(this, lowVoltageLimit, highVoltageLimit);
         float oldValue = this.highVoltageLimit;
         this.highVoltageLimit = highVoltageLimit;
         notifyUpdate("highVoltageLimit", oldValue, highVoltageLimit);
diff --git a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/NodeBreakerVoltageLevel.java b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/NodeBreakerVoltageLevel.java
index 46aa410f..0d5464b5 100644
--- a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/NodeBreakerVoltageLevel.java
+++ b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/NodeBreakerVoltageLevel.java
@@ -476,6 +476,7 @@ public boolean isValid(UndirectedGraph<? extends TerminalExt, SwitchImpl> graph,
                         case GENERATOR:
                         case SHUNT_COMPENSATOR:
                         case DANGLING_LINE:
+                        case STATIC_VAR_COMPENSATOR:
                             feederCount++;
                             break;
 
diff --git a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/RatioTapChangerAdderImpl.java b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/RatioTapChangerAdderImpl.java
index 3214044a..06b6ee8f 100644
--- a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/RatioTapChangerAdderImpl.java
+++ b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/RatioTapChangerAdderImpl.java
@@ -184,19 +184,6 @@ public RatioTapChanger add() {
                             "a regulation terminal has to be set for a regulating ratio tap changer");
                 }
             }
-        } else {
-            if (regulating != null) {
-                throw new ValidationException(parent,
-                        "a regulating status is useless for a ratio tap changer without any load tap changing capabilities");
-            }
-            if (!Float.isNaN(targetV)) {
-                throw new ValidationException(parent,
-                        "a target voltage is useless for a ratio tap changer without any load tap changing capabilities");
-            }
-            if (terminal != null) {
-                throw new ValidationException(parent,
-                        "a regulation terminal is useless for a ratio tap changer without any load tap changing capabilities");
-            }
         }
         if (terminal != null && terminal.getVoltageLevel().getNetwork() != getNetwork()) {
             throw new ValidationException(parent, "regulation terminal is not part of the network");
diff --git a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/ValidationUtil.java b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/ValidationUtil.java
index d7279f2e..0cf8893c 100644
--- a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/ValidationUtil.java
+++ b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/ValidationUtil.java
@@ -159,15 +159,16 @@ static void checkNominalV(Validable validable, float nominalV) {
         }
     }
 
-    static void checkLowVoltageLimit(Validable validable, float lowVoltageLimit) {
-        if (lowVoltageLimit <= 0) {
-            throw new ValidationException(validable, "low voltage limit is <= 0");
+    static void checkVoltageLimits(Validable validable, float lowVoltageLimit, float highVoltageLimit) {
+        if (lowVoltageLimit < 0) {
+            throw new ValidationException(validable, "low voltage limit is < 0");
         }
-    }
-
-    static void checkHighVoltageLimit(Validable validable, float highVoltageLimit) {
-        if (highVoltageLimit <= 0) {
-            throw new ValidationException(validable, "high voltage limit is <= 0");
+        if (highVoltageLimit < 0) {
+            throw new ValidationException(validable, "high voltage limit is < 0");
+        }
+        if (lowVoltageLimit >= highVoltageLimit) {
+            throw new ValidationException(validable, "Inconsistent voltage limit range ["
+                    + lowVoltageLimit + ", " + highVoltageLimit + "]");
         }
     }
 
diff --git a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/VoltageLevelAdderImpl.java b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/VoltageLevelAdderImpl.java
index e28fff79..4a07ecd8 100644
--- a/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/VoltageLevelAdderImpl.java
+++ b/iidm-network-impl/src/main/java/eu/itesla_project/iidm/network/impl/VoltageLevelAdderImpl.java
@@ -76,8 +76,7 @@ public VoltageLevel add() {
         // TODO : ckeck that there are not another voltage level with same base voltage
 
         ValidationUtil.checkNominalV(this, nominalV);
-        ValidationUtil.checkLowVoltageLimit(this, lowVoltageLimit);
-        ValidationUtil.checkHighVoltageLimit(this, highVoltageLimit);
+        ValidationUtil.checkVoltageLimits(this, lowVoltageLimit, highVoltageLimit);
         ValidationUtil.checkTopologyKind(this, topologyKind);
 
         VoltageLevelExt voltageLevel;