In a traction lift, what is the function of the counterweight?
Answer & step-by-step solution
The counterweight balances the lift car plus a designed fraction of rated load, reducing the traction motor torque and energy needed to move the system. It also helps maintain traction on the sheave.
Concept & Reasoning
In a traction lift the car and counterweight are connected by ropes over a drive sheave. A common design balances approximately car mass plus 40–50% of rated payload, although exact balance factor varies. The motor then primarily handles the difference between car-side and counterweight-side weights plus losses/acceleration.
How to Solve It in the Exam
Counterweight reduces unbalanced load on the motor.
Important Exam Point
Counterweight is not the emergency brake; safety gear/governor handle overspeed protection.
Quick Trick
Counterweight reduces unbalanced load on the motor.
Common Mistake
Assuming it exactly equals the fully loaded car weight.
ट्रैक्शन लिफ्ट में काउंटरवेट का कार्य क्या है?
उत्तर और चरणबद्ध हल
B — काउंटरवेट लिफ्ट कार और रेटेड लोड के एक निर्धारित भाग (प्रायः ~40–50%) को संतुलित करता है, जिससे ट्रैक्शन मोटर का टॉर्क और ऊर्जा घटती है और शीव पर ट्रैक्शन बना रहता है।
विस्तृत हल (मूल भाषा में)
Concept & Reasoning
In a traction lift the car and counterweight are connected by ropes over a drive sheave. A common design balances approximately car mass plus 40–50% of rated payload, although exact balance factor varies. The motor then primarily handles the difference between car-side and counterweight-side weights plus losses/acceleration.
How to Solve It in the Exam
Counterweight reduces unbalanced load on the motor.
Important Exam Point
Counterweight is not the emergency brake; safety gear/governor handle overspeed protection.
Quick Trick
Counterweight reduces unbalanced load on the motor.
Common Mistake
Assuming it exactly equals the fully loaded car weight.
ટ્રેક્શન લિફ્ટમાં કાઉન્ટરવેઇટનું કાર્ય શું છે?
જવાબ અને પગલાવાર ઉકેલ
B — કાઉન્ટરવેઇટ લિફ્ટ કાર અને રેટેડ લોડના નિર્ધારિત ભાગ (સામાન્ય રીતે ~40–50%)ને સંતુલિત કરે છે, જેથી ટ્રેક્શન મોટરનો ટોર્ક અને ઊર્જા ઘટે છે અને શીવ પર ટ્રેક્શન જળવાય છે.
વિગતવાર ઉકેલ (મૂળ ભાષામાં)
Concept & Reasoning
In a traction lift the car and counterweight are connected by ropes over a drive sheave. A common design balances approximately car mass plus 40–50% of rated payload, although exact balance factor varies. The motor then primarily handles the difference between car-side and counterweight-side weights plus losses/acceleration.
How to Solve It in the Exam
Counterweight reduces unbalanced load on the motor.
Important Exam Point
Counterweight is not the emergency brake; safety gear/governor handle overspeed protection.
Quick Trick
Counterweight reduces unbalanced load on the motor.
Common Mistake
Assuming it exactly equals the fully loaded car weight.
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