Hi
I want to estimate the relay contact life that is switch some 120VAC solenoids.
The manufacturer provides a graph listing expected operations VS switching current. That's quite easy to follow if you have one solenoid being switched by the contact.
Question #1
But how do you determine...
In order to be in compliance with the CSA or Ontario Electrical Safety Authority (OESC) code,
Can TEW machine wires or SEW appliance wires be installed in a conduit as interconnecting wires to provide 120VAC power from a transmitter to a remote sensor?
I'm looking for 90+ Deg C rated wire to...
Hi
I want to some feedback from others on this site. I have a touchscreen rated to -20C that's mounted outdoors but the response is often very slow and laggy during cold weather months. It often dips down to -10C around here. A slow touchscreen is a major annoyance for the users.
I am...
Does this type of transformer exist? Primary and Secondary voltages are both the same, 600V, but it's Delta to Wye connected, 3-phase, ~400KVA.
The reason for asking is, I want to take advantage of the taps in a transformer to give a small boost to voltage that is too low. Can this be...
I want to send set an alarm bit when the controller faults on minor or major watchdog error.
I was thinking about using the GSV (Get system value) function to read the controller Fault Log. Should this logic be placed in it's own separate task and set as a periodic task type.
If the main...
The CEC code allows the use of overcurrent protection device rated at 125% of the rating of a dry type transformer with primary voltage below 750V, overcurrent protection on the secondary side is not required.
Are the transformers built to withstand the load at 125% for long periods of time...
What is an acceptable level of voltage drop across the line and load side of a motor contactor? Is there an IEEE standard or manufacturer recommendation on this?
How many amps of 120V single phase loads can a 3-phase 30KVA, 600V - 120/208V transformer delivery on L1, L2 & L3?
What about 208V single phase loads?
I understand that you can have 30,000/208/1.73 = 83A of 3-phase 208V balanced loads but I want to understand the single phase 120/208 scenario.
By code and in common practice, is it necessary to have the same ground carried through from the source to the load?
The scenario is this, a 15KV/600V solidly grounded transformer, 600V power is distributed and protected by breakers. One segment of a 600V circuit travels some distance on...
How do you proceed with the voltage drop calculation of a circuit that has various conductor sizes, material, lengths and 1 vs 2 conductors per phase?
Do you start with the known supplied voltage and do the calculation for each section separately, use the calculated voltage result from the...
What's the proper way to terminate parallel conductors in a disconnect? The lugs would only except two wires that's one size smaller than the wires that exists.
A distribution block in a separate junction box just before the disconnect?
Are fusible disconnects 100% rated for continous duty? Circuit breakers are often 80% rated, 15A breaker should only have 12A max of continous load.
What about fuses, are there continous duty ratings on them?
Does the OESC in Ontario allow the use of a general purpose level switch in a Class 1 Div 1 (Zone 1) location if the circuit is designed with intrinsic safety barrier and wiring methods?
Is the amount of voltage drop of following two circuits the same? The load is same in both circuits but the source is different.
Source: 4-Wire 3-Phase 120/208V
Load: 500', 2-Wire 1-Phase 120V (Line-Neutral)
Source: 3-Wire 1-Phase 120/240V
Load: 500', 2-Wire 1-Phase 120V...
How do you calculate the current on each line conductor for a resistive load?
The load is single phase, 575V Line-Line, 1000W Resistive
I = 1000W / 575V / 1.73 = 1.005A
or is it
I = 1000W / 575V = 1.739A because it's single phase?
Is it correct to call it a single phase load because...
I have a simple question about 3-phase supply with 1-phase loads.
If the supply is 3-phase 575V L-L and there are 1-phase loads.
10 A between phase A-B
10 A between phase B-C
10 A between phase A-C
What is the total load on each phase A, B, C? 10A or 20A?
I'm sure I am not the only person who find the the Ontario Electrical Safety Code a difficult read because the multiple layers of sub-sections and the endless references to other sections with the code.
Are there any digests out there that explains sections of the code and provide examples...
In RXLogix 5000, why does it show the blackplane in the I/O configure only for certain types of controllers?
eg. 1756-L61, I can see a backplane 1756-A17 in the I/O configure tree
1756-L1, only the modules are shown, no backplane or controller are shown under the same tree.
Is there a difference between Core Balance CT for ground fault detection and a phase CT used for o/c protection?
I understand for ground fault detection, you have to run all three phase conductors through the CT but does it require a special window type CT?
Is it common and acceptable practice to install fully insulated medium voltage wires through a LV CT?
There is a 4160V starter that requires a 50:5 CT for ground fault detection to a protection relay. The majority of the instrument current transformer I've come across are LV, only 600V...
