diff --git a/core/loadpoint.go b/core/loadpoint.go
index 69d21af59..3223400aa 100644
--- a/core/loadpoint.go
+++ b/core/loadpoint.go
@@ -1449,8 +1449,15 @@ func (lp *Loadpoint) pvScalePhases(sitePower, minCurrent, maxCurrent float64) in
 			lp.log.DEBUG.Printf("available power %.0fW < %.0fW min %dp threshold", availablePower, float64(activePhases)*Voltage*minCurrent, activePhases)
 		}
 
+		// while charging, scaling down only helps if 1p is sustainable, otherwise it
+		// merely delays the pv disable timer by the phase timer duration
+		useful := !lp.enabled || !lp.charging() || powerToCurrent(availablePower, 1) >= minCurrent
+		if insufficient && !useful {
+			lp.log.DEBUG.Printf("available power %.0fW < %.0fW min 1p threshold, disabling instead of scaling down", availablePower, Voltage*minCurrent)
+		}
+
 		// scaling down also frees load management headroom for min power on activePhases
-		scalable = insufficient || !lp.circuitAllowsPhases(activePhases, minCurrent)
+		scalable = insufficient && useful || !lp.circuitAllowsPhases(activePhases, minCurrent)
 	}
 
 	// scale down phases
diff --git a/core/loadpoint_phases_test.go b/core/loadpoint_phases_test.go
index da713e4a7..cc723ea14 100644
--- a/core/loadpoint_phases_test.go
+++ b/core/loadpoint_phases_test.go
@@ -271,6 +271,7 @@ func TestPvScalePhases(t *testing.T) {
 			// scale down
 			min1p := 0.1
 			lp.phaseTimer = time.Time{}
+			lp.chargePower = float64(lp.ActivePhases()) * minA * Voltage // charging at min current
 
 			plainCharger.EXPECT().Enable(false).Return(nil).MaxTimes(1)
 			phaseCharger.EXPECT().Phases1p3p(1).Return(nil).MaxTimes(1)
@@ -372,6 +373,17 @@ func TestPvScalePhasesTimer(t *testing.T) {
 			lp.phaseTimer = elapsed
 		}},
 
+		// charging with insufficient power for 1p: disable instead of scaling down
+		{"3/3->1, insufficient for 1p, charging", 3, 3, 0.1, 3, 0, func(lp *Loadpoint) {
+			lp.phaseTimer = elapsed
+			lp.enabled = true
+		}},
+		{"3/3->1, sufficient for 1p, charging", 3, 3, 3 * Voltage * minA / 2, 1, 1, func(lp *Loadpoint) {
+			lp.phaseTimer = elapsed
+			lp.enabled = true
+			lp.chargePower = 3 * Voltage * minA
+		}},
+
 		// switch down from 3p/0p while not yet charging
 		{"3/0->1, not enough power, not charging", 3, 0, 0, 1, 1, func(lp *Loadpoint) {
 			lp.status = api.StatusB
diff --git a/core/loadpoint_test.go b/core/loadpoint_test.go
index d427b0f1d..ccb160dcf 100644
--- a/core/loadpoint_test.go
+++ b/core/loadpoint_test.go
@@ -752,8 +752,9 @@ func TestPVHysteresisAfterPhaseSwitch(t *testing.T) {
 			Disable: loadpoint.ThresholdConfig{
 				Delay: dt,
 			},
-			status:  api.StatusC,
-			enabled: true,
+			status:      api.StatusC,
+			enabled:     true,
+			chargePower: 3 * Voltage * minA, // charging 3p at min current
 		}
 
 		start := clock.Now()