谁比较熟悉UL1012标准,输出电路接地怎么理解?
20 Output Circuit Grounding20.1 The requirements for circuit grounding specified in 20.2 – 20.12 apply to the output circuit of fixed
units and of units having standard configuration grounding type receptacles for the output ac power
connections.
20.2 An output ac power circuit shall be grounded when:
a) The circuit has no electrical connection, including a solidly connected grounded circuit
conductor, to supply conductors originating in another wiring system;
b) The circuit is rated 50 – 600 volts; and
c) The circuit is as described in (1) – (3). See requirements for Alternating-Current Circuits and
Systems to Be Grounded in the National Electrical Code, ANSI/NFPA 70, for other circuits:
1) A circuit that is grounded so that the maximum voltage to ground on the
ungrounded conductors does not exceed 150 volts. This requires that one conductor of
each of the following circuits be grounded:
i) 120 volts, 2-wire;
ii) 240/120 volts, single-phase, 3-wire;
iii) 208/120 volts, two-phase, 3-wire;
iv) 208/120 volts, three-phase, 4-wire.
2) A circuit nominally rated 480 wye/277 volts, 3-phase, 4-wire in which the neutral is
used as a circuit conductor.
3) A circuit-nominally rated 240/120 volts, 3-phase, 4-wire in which the midpoint of one
phase is used as a circuit conductor.
For other units, an output ac power circuit complying with (a) is able to be grounded when the construction
complies with the requirements described in 20.3 and 20.11.
20.3 With reference to 20.2, the conductor to be grounded shall be as follows:
a) Single-phase ac system, 2-wire – one conductor.
b) Single-phase ac system, 3-wire – the neutral conductor.
c) Multiphase ac system having one wire common to all phases – the common conductor.
d) Multiphase ac system where one phase is used as in (b) above – the neutral conductor.
不知道你要说什么问题,关键是你的问题是什么? fasten 发表于 2017-10-19 11:11
不知道你要说什么问题,关键是你的问题是什么?
这个AC输出的一跟线接地应该怎么接,有谁做过这类产品,是怎么处理的?
如果外壳是金属接地的,如果AC接地,岂不是把AC与外壳直接相连了,怎么满足危险电压到金属外壳的基本绝缘的要求了;
如果不接地,则配电系统就从TN变成了IT了,漏电保护装置不起作用,也不满足标准这个条款要求了;
如果是便携式设备,塑胶外壳的,在因为是便携,产品用于无电区域,是无法接地的,怎么去满足或者规避此条款要求,类似产品有工地使用的柴油发电机,其输出的相线是否需要接地? 尚須高手出面解釋囉~:L lanfeiyuner 发表于 2017-10-19 11:30
这个AC输出的一跟线接地应该怎么接,有谁做过这类产品,是怎么处理的?
如果外壳是金属接地的,如果AC接 ...
说了一大堆,还是云里雾里。根本不知你要说什么?输入是什么情况也没有 ralf 发表于 2017-10-20 09:21
说了一大堆,还是云里雾里。根本不知你要说什么?输入是什么情况也没有
好吧,考虑欠周,产品是逆变器,输入为DC,对于有AC输入的UPS来说,直接把电网的N线直接连接到输出端口上,确实就没有我说的问题了。
现在是纯逆变器,无电网接入的,怎么解决此问题? lanfeiyuner 发表于 2017-10-20 13:24
好吧,考虑欠周,产品是逆变器,输入为DC,对于有AC输入的UPS来说,直接把电网的N线直接连接到输出端口上 ...
我印象中,你这标准选择就不对,用UL1012 ralf 发表于 2017-10-20 13:44
我印象中,你这标准选择就不对,用UL1012
那应该选择哪个标准更合适?
即使使用的不是UL1012标准,只要是AC输出都需要考虑同样的问题。
有竞争对手的产品,也是用的UL1012标准,其输出未考虑接地问题,至于其怎么过的认证,就说不清了! lanfeiyuner 发表于 2017-10-20 14:13
那应该选择哪个标准更合适?
即使使用的不是UL1012标准,只要是AC输出都需要考虑同样的问题。
有竞争对 ...
UL 458, 像你这小功率;大功率的话UL 1741 ralf 发表于 2017-10-20 15:18
UL 458, 像你这小功率;大功率的话UL 1741
UL1741是分布式能源的,一般是储能变流器,光伏逆变器使用此标准,这个便携式应该不是很合适吧!
UL458是车载逆变器的标准,我们这个虽然不是车载的,但是是其因为是便携式的,所以看起来好像使用UL458是更合适点,特意对接地这个问题找了第24章,这章没理解,是需要接地和GFCI吗,没有理解车载的设备怎么提供接地,GFCI怎么工作(产品是带标准outlet的。)
24 Inverter Output Circuits
24.1 A unit having output circuits for supplying 120 V, 60 Hz, 2-wire with ground or 120/240 V, 60 Hz,
3-wire with ground to vehicles and recreational vehicle wiring systems shall have the output circuits
protected by integral ground-fault circuit-interrupters intended for the current involved.
Exception No. 1: A unit that does not have an integral output receptacle, and that has a wiring
compartment with pigtail leads, wiring terminals, or other equivalent means for output field-wiring
connections need not be provided with integral output circuit ground-fault circuit-interrupter protection if:
a) The unit is marked in accordance with 58.21, and
b) The installation and operating instructions manual for the unit comply with 59.1.
Exception No. 2: A portable unit need not be provided with integral ground-fault circuit-interrupter
protection if the unit:
a) Is intended to be connected to the cigarette lighter outlet of a vehicle, and
b) Has no direct electrical connection between the input and output circuits.
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