peterh5322
Diamond
- Joined
- Dec 15, 2002
- Location
- Monterey Bay, California
I have posted on the Hardinge-Lathe Yahoo! Group the following message ...
http://groups.yahoo.com/group/Hardinge-Lathe/message/272
... which includes the following text ...
Revised 2/20/2004 (Paragraphs prefixed by "| ").
Hardinge released a magnetic-type starter for the TL (T-10) in about March 1947, replacing the manual-type starter found on earlier machines.
(March 1947 isn't necessarily the precise date for its introduction, however, this date, "3/47", is printed on the bottom of the diagram posted by Jim in his "Jim's T-10" photo section).
Normally, for a "consequent-pole" motor, one five-pole and one three-pole magnetic starters are required. Hardinge implemented this starter with one three-pole magnetic starter, and a drum switch of unusual configuration.
Now, that is for the high/low speed function alone; the forward/reverse function is also implemented using a drum switch, although its configuration is conventional.
Referring to the schematic posted by Jim ...
Hardinge drew this schematic diagram in an unconventional way, breaking the high/low drum switch into four sections of two apparent poles each, and the forward/reverse drum switch into three sections, with two apparent poles in the first two sections and one pole in the last section.
However, there are really only five poles in the high/low switch and three poles in the forward/reverse switch, which is consistent with most manual-type consequent-pole starters which provide for reversing.
In order to better describe the March 1947 Hardinge control, I will re-label the sections and poles of the high/low switch as follows, from top to bottom:
1) Sections 1a and 1b: wires 3, T5 and T3; fast and slow, respectively,
2) Section 2: fast only,
3) Section 3: fast only,
4) Sections 4a and 4b: wires 1, T1 and T6; slow and fast, respectively,
5) Sections 5a and 5b: wires 2, T2 and T4; slow and fast, respectively.
(Wires 1, 2, and 3 come from the reversing switch, and represent the three phases, but not necessarily Phases A, B and C, as will be described later).
In the center, or off position, no connections are made.
In the fast position, wire 3 is connected to T5 by section 1a, using a terminal of section 1b; wire 1 is connected to T6 by section 4b; and wire 2 is connected to T4 by section 5b, additionally, T1, T2 and T3 are connected together by sections 2 and 3.
In the slow position, wire 3 is connected to T3 by section 1b, using a terminal of section 2; wire 1 is connected to T1 by section 4a, using a terminal of section 4b; and wire 2 is connected to T2 by section 5a, using a terminal of section 5b.
| The above described connections accomplishes the switching of the classical four-pole consequent-pole, constant-torque, two-speed motor. The motor is operated in four-pole parallel-star (2Y) mode for high speed, and in eight-pole series-delta mode for low speed.
The reversing drum switch is perhaps a little easier to understand.
I will re-label the sections and poles of the reversing switch as follows:
| 1) Sections 1a and 1b: wire L1; forward and reverse, respectively,
2) Sections 2a and 2b: wire L3; forward and reverse, respectively, and
3) Section 3: wire L2; forward or reverse.
| In the center, or off position, no connections are made.
In the forward position, wire L1 is connected to wire 1 by section 1a, using a terminal of section 1b and a terminal of section 2b; wire L3 is connected to wire 3 by section 2a, using a terminal of section 2b; and wire L2 is connected to wire 2 by section 3.
In the reverse position, wire L1 is connected to wire 3 by section 1b, using a terminal of section 2a; wire L3 is connected to wire 1 by section 2b; and wire L2 is connected to wire 2 by section 3.
The above described connections accomplishes the reversing of the generalized three-phase motor.
(Wires L1, L2 and L3 represent phases A, B and C, respectively; wires 1, 2 and 3 represent these phases, after reversing, if any, has been applied. Phase B/L2 are not reversed).
Hardinge's March 1947 design incorporates a standard NEMA Type 0 magnetic starter, for both low-voltage control (high-voltage control is an option) and for motor running protection, avoiding the complications of a purpose-built consequent-pole-type magnetic starter, while retaining the extant manual consequent-pole and reversing drum switches, which were apparently adapted from an earlier version of the TL.
This innovative control design has the obvious advantages of a magnetic starter, and low-voltage control (unless high-voltage control was specified), at significantly lower cost. However, the schematic diagram is somewhat counterintuitive.
Many thank to Jim for posting the March 1947 schematic diagram.
Peter.
http://groups.yahoo.com/group/Hardinge-Lathe/message/272
... which includes the following text ...
Revised 2/20/2004 (Paragraphs prefixed by "| ").
Hardinge released a magnetic-type starter for the TL (T-10) in about March 1947, replacing the manual-type starter found on earlier machines.
(March 1947 isn't necessarily the precise date for its introduction, however, this date, "3/47", is printed on the bottom of the diagram posted by Jim in his "Jim's T-10" photo section).
Normally, for a "consequent-pole" motor, one five-pole and one three-pole magnetic starters are required. Hardinge implemented this starter with one three-pole magnetic starter, and a drum switch of unusual configuration.
Now, that is for the high/low speed function alone; the forward/reverse function is also implemented using a drum switch, although its configuration is conventional.
Referring to the schematic posted by Jim ...
Hardinge drew this schematic diagram in an unconventional way, breaking the high/low drum switch into four sections of two apparent poles each, and the forward/reverse drum switch into three sections, with two apparent poles in the first two sections and one pole in the last section.
However, there are really only five poles in the high/low switch and three poles in the forward/reverse switch, which is consistent with most manual-type consequent-pole starters which provide for reversing.
In order to better describe the March 1947 Hardinge control, I will re-label the sections and poles of the high/low switch as follows, from top to bottom:
1) Sections 1a and 1b: wires 3, T5 and T3; fast and slow, respectively,
2) Section 2: fast only,
3) Section 3: fast only,
4) Sections 4a and 4b: wires 1, T1 and T6; slow and fast, respectively,
5) Sections 5a and 5b: wires 2, T2 and T4; slow and fast, respectively.
(Wires 1, 2, and 3 come from the reversing switch, and represent the three phases, but not necessarily Phases A, B and C, as will be described later).
In the center, or off position, no connections are made.
In the fast position, wire 3 is connected to T5 by section 1a, using a terminal of section 1b; wire 1 is connected to T6 by section 4b; and wire 2 is connected to T4 by section 5b, additionally, T1, T2 and T3 are connected together by sections 2 and 3.
In the slow position, wire 3 is connected to T3 by section 1b, using a terminal of section 2; wire 1 is connected to T1 by section 4a, using a terminal of section 4b; and wire 2 is connected to T2 by section 5a, using a terminal of section 5b.
| The above described connections accomplishes the switching of the classical four-pole consequent-pole, constant-torque, two-speed motor. The motor is operated in four-pole parallel-star (2Y) mode for high speed, and in eight-pole series-delta mode for low speed.
The reversing drum switch is perhaps a little easier to understand.
I will re-label the sections and poles of the reversing switch as follows:
| 1) Sections 1a and 1b: wire L1; forward and reverse, respectively,
2) Sections 2a and 2b: wire L3; forward and reverse, respectively, and
3) Section 3: wire L2; forward or reverse.
| In the center, or off position, no connections are made.
In the forward position, wire L1 is connected to wire 1 by section 1a, using a terminal of section 1b and a terminal of section 2b; wire L3 is connected to wire 3 by section 2a, using a terminal of section 2b; and wire L2 is connected to wire 2 by section 3.
In the reverse position, wire L1 is connected to wire 3 by section 1b, using a terminal of section 2a; wire L3 is connected to wire 1 by section 2b; and wire L2 is connected to wire 2 by section 3.
The above described connections accomplishes the reversing of the generalized three-phase motor.
(Wires L1, L2 and L3 represent phases A, B and C, respectively; wires 1, 2 and 3 represent these phases, after reversing, if any, has been applied. Phase B/L2 are not reversed).
Hardinge's March 1947 design incorporates a standard NEMA Type 0 magnetic starter, for both low-voltage control (high-voltage control is an option) and for motor running protection, avoiding the complications of a purpose-built consequent-pole-type magnetic starter, while retaining the extant manual consequent-pole and reversing drum switches, which were apparently adapted from an earlier version of the TL.
This innovative control design has the obvious advantages of a magnetic starter, and low-voltage control (unless high-voltage control was specified), at significantly lower cost. However, the schematic diagram is somewhat counterintuitive.
Many thank to Jim for posting the March 1947 schematic diagram.
Peter.
